Practical Exercises in Elementary Meteorology

CHAPTER XXVI.

Chapter 3016,905 wordsPublic domain

METEOROLOGICAL TABLES.

The tables which follow are those which are now in use by the United States Weather Bureau. They were first published in the _Instructions for Voluntary Observers_ issued in 1892, and were reprinted in 1897. The following instructions will be found of service in the use of the tables:——

TABLE I.——DEW-POINT.

The figures in heavy type, arranged in vertical columns at each side of the page, are the _air temperatures_ in degrees Fahrenheit, as recorded by the dry-bulb thermometer. The figures in heavy type, running across the page, denote the _differences_, in degrees and tenths of degrees, _between the dry-bulb and wet-bulb readings_, or, technically, the _depression of the wet-bulb thermometer_. The figures in the vertical columns denote the _dew-points_. Make your observation of the wet and dry-bulb thermometers and note the difference between the two readings. Find, in the vertical columns of heavy type, the temperature corresponding to your dry-bulb reading, or the nearest temperature to that. Then look along the horizontal lines of figures in heavy type for the figure which corresponds exactly, or most nearly, with the difference between your wet and dry-bulb readings. Look down the vertical column under this latter figure until you reach the horizontal line corresponding to your dry-bulb reading. At this point the figures in the vertical column give the dew-point of the air at the time of your observation.

_Example_: Air Temperature (dry bulb), 47°; Wet Bulb, 44°; Difference, 3°. On page 148 will be found the table containing both 47° (dry bulb) and 3° (depression of the dew-point). In the twenty-eighth line of this table and in the seventh column will be found the dew-point, viz., 41°.

_Example_: Air Temperature, 61.5°; Wet Bulb, 55.5°; Difference, 6°.

In this case 61.5° is not found in the vertical columns of dry-bulb readings, but 61° and 62° are found. The dew-point, with a difference between wet and dry-bulb readings of 6°, for an air temperature of 61°, is 50°; for an air temperature of 62°, it is 52°. Evidently, then, for an air temperature of 61.5° the dew-point will be 51°, _i.e._, halfway between 50° and 52°. This method of determining dew-points at air temperatures or with depressions of the wet-bulb thermometer which are not given exactly in the tables, is known as _interpolation_.

_Example_: Air Temperature, 93°; Wet Bulb, 90.5°; Difference, 2.5°. Our table gives no dew-points for wet-bulb depressions of 2.5°, with air temperature 93°, but we find (on page 152) that for air temperature 93° and depression of wet bulb of 2°, the dew-point is 91°, while for a wet-bulb depression of 3°, the dew-point is 89°. By the method of interpolation we can readily determine the dew-point in the special case under consideration as 90°, _i.e._, halfway between 89° and 91°.

TABLE II.——RELATIVE HUMIDITY.

The general plan of this table is the same as that of Table I. The figures in the vertical columns are the relative humidities (in percentages) corresponding to the different readings of the wet and dry-bulb thermometers.

TABLE III.——REDUCTION OF BAROMETER TO 32°.

The figures in heavy type, arranged in vertical columns at the left of the page, refer to the temperature in degrees Fahrenheit, as indicated by the attached thermometer. The figures in heavy type, running across the top of the page, are the barometer readings in inches and tenths. Make a reading of the attached thermometer and of the barometer. Find in the vertical column the temperature corresponding to the reading of the attached thermometer, and in the horizontal line of heavy figures the reading corresponding to the height of the barometer. The decimal in the vertical column, under the appropriate barometer reading, and in the same horizontal line with the appropriate thermometer reading, is to be subtracted from the height of the barometer as observed, thus correcting the reading to freezing. When the attached thermometer reads below 28°, the correction is additive.

_Example_: Attached Thermometer, 69°; Barometer, 30.00 inches; Correction, -.110; Corrected reading, 29.890 inches.

_Example_: Attached Thermometer, 73°; Barometer, 29.75 inches; Correction = ?

We do not find any column corresponding to a barometer reading of 29.75 inches. We do find, however, that with a barometer reading of 29.50, and an attached thermometer reading of 73, the correction is -.118 inch, and with a barometer reading of 30.00, the correction is -.120. By interpolating, as in the case of the humidity table above, we find the correction for a barometer reading of 29.75 inches, and an attached thermometer reading of 73°. The correction is -.119, and the corrected reading is 29.75 - .119 = 29.63 inches.

TABLE IV.——REDUCTION OF BAROMETER TO SEA LEVEL.

The figures in heavy type, in the left-hand vertical columns, are the heights, in feet, of the barometer above sea level. The figures in heavy type at the top of the columns, running across the page, are the readings of the ordinary thermometer. The numbers of inches and hundredths of inches to be subtracted from the barometer reading (corrected for temperature by Table III), for the different heights above sea level, are given in the vertical columns.

The altitude above sea level of the city or town at which the observation is made should be ascertained as accurately as possible from some recognized authority, as, _e.g._, from a railroad survey; from Government measurements, or from some engineer’s office. The correction to be made is determined by a simple inspection of the table or by the method of interpolation.

_Example_: Altitude of Barometer above sea level, 840 feet; Temperature of the air, 40°; Correction, +.931 inch.

_Example_: Altitude of Barometer above sea level, 205 feet; Temperature of the air, 45°; Correction = ?

Here 205 feet and 45° are neither of them found in the table. Hence a double interpolation is necessary. For 200 feet and 40° the correction is +.224 inch. For 200 feet and 50° the correction is +.220 inch. Hence for 200 feet and 45° the correction is +.222 inch. For 210 feet and 40° the correction is +.235 inch. For 210 feet and 50° the correction is +.231 inch. Hence for 210 feet and 45° the correction is +.233 inch. Now for 205 feet we should have a correction midway between +.235 inch and +.233 inch or +.234 inch.

TABLE I.——TEMPERATURE OF THE DEW-POINT, IN DEGREES FAHRENHEIT.

======+================================================================+====== _t_ | Difference between the dry and wet thermometers (_t-t′_) | _t_ (Dry +----+----+----+----+----+----+----+----+----+----+----+----+----+(Dry ther.)|0°.2|0°.4|0°.6|0°.8|1°.0|1°.2|1°.4|1°.6|1°.8|2°.0|2°.2|2°.4|2°.6|ther.) ------+----+----+----+----+----+----+----+----+----+----+----+----+----+------ -40 | -52| | | | | | | | | | | | | -40 -39 | -50| | | | | | | | | | | | | -39 -38 | -49| | | | | | | | | | | | | -38 -37 | -48| | | | | | | | | | | | | -37 -36 | -46| | | | | | | | | | | | | -36 | | | | | | | | | | | | | | -35 | -44| | | | | | | | | | | | | -35 -34 | -43| -58| | | | | | | | | | | | -34 -33 | -42| -55| | | | | | | | | | | | -33 -32 | -40| -52| | | | | | | | | | | | -32 -31 | -38| -49| | | | | | | | | | | | -31 | | | | | | | | | | | | | | -30 | -36| -47| | | | | | | | | | | | -30 -29 | -35| -44| | | | | | | | | | | | -29 -28 | -33| -42| -56| | | | | | | | | | | -28 -27 | -32| -40| -52| | | | | | | | | | | -27 -26 | -30| -37| -48| | | | | | | | | | | -26 | | | | | | | | | | | | | | -25 | -29| -35| -45| | | | | | | | | | | -25 -24 | -28| -34| -43| -58| | | | | | | | | | -24 -23 | -27| -32| -40| -53| | | | | | | | | | -23 -22 | -26| -30| -37| -49| | | | | | | | | | -22 -21 | -25| -29| -35| -45| | | | | | | | | | -21 | | | | | | | | | | | | | | -20 | -23| -28| -33| -41| -55| | | | | | | | | -20 -19 | -22| -26| -31| -38| -50| | | | | | | | | -19 -18 | -21| -25| -29| -35| -45| | | | | | | | | -18 -17 | -20| -23| -27| -32| -41| -55| | | | | | | | -17 -16 | -19| -22| -26| -30| -37| -49| | | | | | | | -16 | | | | | | | | | | | | | | -15 | -17| -20| -24| -28| -34| -44| | | | | | | | -15 -14 | -16| -19| -22| -26| -31| -39| -52| | | | | | | -14 -13 | -15| -18| -21| -25| -29| -35| -46| | | | | | | -13 -12 | -14| -17| -20| -23| -27| -32| -41| -55| | | | | | -12 -11 | -13| -16| -18| -21| -25| -30| -36| -48| | | | | | -11 | | | | | | | | | | | | | | -10 | -12| -14| -17| -20| -23| -27| -33| -42| -58| | | | | -10 -9 | -11| -13| -15| -18| -21| -25| -30| -37| -48| | | | | -9 -8 | -10| -12| -14| -17| -20| -23| -27| -33| -42| -58| | | | -8 -7 | -9| -11| -13| -15| -18| -21| -25| -30| -36| -48| | | | -7 -6 | -8| -10| -12| -14| -16| -19| -23| -27| -32| -41| -56| | | -6 | | | | | | | | | | | | | | -5 | -7| -8| -10| -12| -15| -17| -21| -24| -29| -35| -47| | | -5 -4 | -6| -7| -9| -11| -13| -16| -19| -22| -26| -31| -39| -54| | -4 -3 | -4| -6| -8| -10| -12| -14| -17| -20| -23| -28| -33| -44| | -3 -2 | -3| -5| -6| -8| -10| -12| -15| -18| -21| -24| -29| -36| -48| -2 -1 | -2| -4| -5| -7| -9| -11| -13| -16| -18| -22| -26| -31| -39| -1 | | | | | | | | | | | | | | ±0 | -1| -3| -4| -6| -7| -9| -11| -14| -16| -19| -23| -27| -33| 0 +1 | -0| -2| -3| -4| -6| -8| -10| -12| -14| -17| -20| -24| -28| +1 2 | +1| -1| -2| -3| -5| -6| -8| -10| -12| -15| -17| -21| -25| 2 3 | 2| +1| -1| -2| -3| -5| -7| -8| -10| -13| -15| -18| -21| 3 4 | 3| +2| 0| -1| -2| -4| -5| -7| -9| -11| -13| -16| -19| 4 | | | | | | | | | | | | | | 5 | 4| 3| +1| 0| -1| -2| -4| -5| -7| -9| -11| -14| -16| 5 6 | 5| 4| 3| +1| 0| -1| -3| -4| -6| -7| -9| -12| -14| 6 7 | 6| 5| 4| 3| +1| 0| -1| -3| -4| -6| -8| -10| -12| 7 8 | 7| 6| 5| 4| 3| +1| 0| -1| -3| -4| -6| -8| -10| 8 9 | 8| 7| 6| 5| 4| 3| +1| 0| -1| -3| -4| -6| -8| 9 | | | | | | | | | | | | | | 10 | 9| 8| 7| 6| 5| 4| 3| +1| 0| -1| -3| -4| -6| 10 11 | 10| 9| 8| 7| 6| 5| 4| 3| +2| 0| -1| -3| -4| 11 12 | 11| 10| 9| 9| 8| 7| 5| 4| 3| +2| 0| -1| -2| 12 13 | 12| 11| 11| 10| 9| 8| 7| 6| 5| 3| +2| +1| -1| 13 14 | 13| 12| 12| 11| 10| 9| 8| 7| 6| 5| 4| 2| +1| 14 | | | | | | | | | | | | | | 15 | 14| 13| 13| 12| 11| 10| 9| 8| 7| 6| 5| 4| 3| 15 16 | 15| 15| 14| 13| 12| 11| 10| 10| 9| 8| 7| 5| 4| 16 17 | 16| 16| 15| 14| 13| 12| 12| 11| 10| 9| 8| 7| 6| 17 18 | 17| 17| 16| 15| 14| 14| 13| 12| 11| 10| 9| 8| 7| 18 19 | 18| 18| 17| 16| 15| 15| 14| 13| 12| 11| 10| 10| 9| 19 | | | | | | | | | | | | | | 20 | 19| 19| 18| 17| 17| 16| 15| 14| 13| 13| 12| 11| 10| 20 ------+----+----+----+----+----+----+----+----+----+----+----+----+----+ —————— _t._ |0°.2|0°.4|0°.6|0°.8|1°.0|1°.2|1°.4|1°.6|1°.8|2°.0|2°.2|2°.4|2°.6| _t._ ======+====+====+====+====+====+====+====+====+====+====+====+====+====+======

TABLE I.——TEMPERATURE OF THE DEW-POINT, IN DEGREES FAHRENHEIT.

======+===========================================================+====== _t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_ (Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+(Dry ther.)| 2°.6| 2°.8| 3°.0| 3°.2| 3°.4| 3°.6| 3°.8| 4°.0| 4°.2| 4°.4|ther.) ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ -2 | -48 | | | | | | | | | | -2 -1 | -39 | -54 | | | | | | | | | -1 | | | | | | | | | | | 0 | -33 | -43 | | | | | | | | | 0 +1 | -28 | -35 | -46 | | | | | | | | +1 2 | -25 | -30 | -37 | -50 | | | | | | | 2 3 | -21 | -26 | -31 | -39 | -54 | | | | | | 3 4 | -19 | -22 | -27 | -32 | -42 | -60 | | | | | 4 | | | | | | | | | | | 5 | -16 | -19 | -23 | -28 | -34 | -45 | | | | | 5 6 | -14 | -17 | -20 | -24 | -29 | -35 | -47 | | | | 6 7 | -12 | -14 | -17 | -20 | -24 | -29 | -37 | -50 | | | 7 8 | -10 | -12 | -15 | -17 | -21 | -25 | -30 | -38 | -53 | | 8 9 | -8 | -10 | -12 | -15 | -18 | -21 | -25 | -31 | -39 | -55 | 9 | | | | | | | | | | | 10 | -6 | -8 | -10 | -12 | -15 | -18 | -21 | -26 | -31 | -40 | 10 11 | -4 | -6 | -8 | -10 | -12 | -15 | -18 | -21 | -26 | -31 | 11 12 | -2 | -4 | -6 | -8 | -10 | -12 | -15 | -18 | -21 | -26 | 12 13 | -1 | -2 | -4 | -5 | -7 | -9 | -12 | -14 | -17 | -21 | 13 14 | +1 | 0 | -2 | -3 | -5 | -7 | -9 | -11 | -14 | -17 | 14 | | | | | | | | | | | 15 | 3 | +1 | 0 | -2 | -3 | -5 | -7 | -9 | -11 | -14 | 15 16 | 4 | 3 | +2 | 0 | -1 | -3 | -4 | -6 | -8 | -10 | 16 17 | 6 | 5 | 3 | +2 | +1 | -1 | -2 | -4 | -6 | -8 | 17 18 | 7 | 6 | 5 | 4 | 2 | +1 | 0 | -2 | -3 | -5 | 18 19 | 9 | 8 | 7 | 5 | 4 | 3 | +1 | 0 | -1 | -3 | 19 | | | | | | | | | | | 20 | 10 | 9 | 8 | 7 | 6 | 5 | 3 | +2 | +1 | -1 | 20 ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ _t._ | 2°.6| 2°.8| 3°.0| 3°.2| 3°.4| 3°.6| 3°.8| 4°.0| 4°.2| 4°.4| _t._ ======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======

======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+====== _t._ | 4°.6| 4°.8| 5°.0| 5°.2| 5°.4| 5°.6| 5°.8| 6°.0| 6°.2| 6°.4| _t._ ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ 8 | | | | | | | | | | | 8 9 | | | | | | | | | | | 9 | | | | | | | | | | | 10 | -57 | | | | | | | | | | 10 11 | -41 | -60 | | | | | | | | | 11 12 | -31 | -41 | -59 | | | | | | | | 12 13 | -25 | -31 | -40 | -58 | | | | | | | 13 14 | -20 | -25 | -30 | -39 | -56 | | | | | | 14 | | | | | | | | | | | 15 | -16 | -20 | -24 | -30 | -38 | -53 | | | | | 15 16 | -13 | -16 | -19 | -23 | -28 | -36 | -50 | | | | 16 17 | -10 | -12 | -15 | -18 | -22 | -27 | -34 | -47 | | | 17 18 | -7 | -9 | -12 | -14 | -17 | -21 | -26 | -32 | -44 | | 18 19 | -5 | -7 | -9 | -11 | -14 | -17 | -20 | -25 | -30 | -40 | 19 | | | | | | | | | | | 20 | -2 | -4 | -6 | -8 | -10 | -13 | -16 | -19 | -23 | -29 | 20 ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ _t._ | 4°.6| 4°.8| 5°.0| 5°.2| 5°.4| 5°.6| 5°.8| 6°.0| 6°.2| 6°.4| _t_. ======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======

TABLE I.——TEMPERATURE OF THE DEW-POINT, IN DEGREES FAHRENHEIT.

======+===========================================================+====== _t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_ (Dry +----+----+----+----+----+----+----+----+----+----+----+----+(Dry ther.)|0°.5|1°.0|1°.5|2°.0|2°.5|3°.0|3°.5|4°.0|4°.5|5°.0|5°.5|6°.0|ther.) ------+----+----+----+----+----+----+----+----+----+----+----+----+------ 20 | 18 | 17 | 15 | 13 | 10 | 8 | 5 | 2 | -2 | -6 |-12 |-19 | 20 21 | 19 | 18 | 16 | 14 | 12 | 9 | 7 | 4 | 0 | -4 | -8 |-15 | 21 22 | 20 | 19 | 17 | 15 | 13 | 11 | 8 | 6 | +2 | -1 | -6 |-11 | 22 23 | 22 | 20 | 18 | 16 | 14 | 12 | 10 | 7 | 4 | +1 | -3 | -8 | 23 24 | 23 | 21 | 19 | 18 | 16 | 14 | 11 | 9 | 6 | 3 | -1 | -5 | 24 | | | | | | | | | | | | | 25 | 24 | 22 | 21 | 19 | 17 | 15 | 13 | 11 | 8 | 5 | +2 | -2 | 25 26 | 25 | 23 | 22 | 20 | 18 | 16 | 14 | 12 | 10 | 7 | 4 | 0 | 26 27 | 26 | 24 | 23 | 21 | 20 | 18 | 16 | 14 | 11 | 9 | 6 | +3 | 27 28 | 27 | 25 | 24 | 22 | 21 | 19 | 17 | 15 | 13 | 11 | 8 | 5 | 28 29 | 28 | 26 | 25 | 24 | 22 | 20 | 19 | 17 | 14 | 12 | 10 | 7 | 29 | | | | | | | | | | | | | 30 | 29 | 27 | 26 | 25 | 23 | 22 | 20 | 18 | 16 | 14 | 11 | 9 | 30 31 | 30 | 29 | 27 | 26 | 24 | 23 | 21 | 19 | 18 | 15 | 13 | 11 | 31 32 | 31 | 30 | 28 | 27 | 26 | 24 | 22 | 21 | 19 | 17 | 15 | 13 | 32 33 | 31 | 31 | 29 | 28 | 26 | 25 | 23 | 22 | 19 | 18 | 16 | 14 | 33 34 | 32 | 32 | 30 | 29 | 27 | 26 | 24 | 24 | 21 | 20 | 18 | 16 | 34 | | | | | | | | | | | | | 35 | 33 | 32 | 31 | 30 | 29 | 28 | 26 | 25 | 23 | 22 | 20 | 18 | 35 36 | 35 | 34 | 32 | 31 | 30 | 29 | 27 | 26 | 24 | 23 | 21 | 19 | 36 37 | 36 | 35 | 33 | 32 | 31 | 30 | 28 | 27 | 26 | 24 | 22 | 21 | 37 38 | 37 | 36 | 34 | 33 | 32 | 31 | 30 | 28 | 27 | 26 | 24 | 22 | 38 39 | 38 | 37 | 35 | 34 | 33 | 32 | 30 | 29 | 28 | 27 | 25 | 24 | 39 | | | | | | | | | | | | | 40 | 39 | 38 | 36 | 35 | 34 | 33 | 31 | 30 | 29 | 28 | 26 | 25 | 40 41 | 40 | 39 | 37 | 36 | 35 | 34 | 32 | 32 | 30 | 29 | 28 | 26 | 41 42 | 41 | 40 | 39 | 38 | 36 | 35 | 34 | 33 | 31 | 30 | 29 | 27 | 42 43 | 42 | 41 | 40 | 39 | 37 | 36 | 35 | 34 | 32 | 31 | 30 | 29 | 43 44 | 43 | 42 | 41 | 40 | 38 | 37 | 36 | 35 | 33 | 32 | 31 | 30 | 44 | | | | | | | | | | | | | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 32 | 31 | 45 46 | 45 | 44 | 43 | 42 | 41 | 40 | 38 | 37 | 36 | 35 | 33 | 32 | 46 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 47 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 38 | 37 | 36 | 35 | 48 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 39 | 38 | 37 | 36 | 49 | | | | | | | | | | | | | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 38 | 37 | 50 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 39 | 38 | 51 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 52 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 53 54 | 53 | 52 | 51 | 50 | 50 | 49 | 47 | 46 | 45 | 44 | 43 | 42 | 54 | | | | | | | | | | | | | 55 | 54 | 53 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 44 | 43 | 55 56 | 55 | 54 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 45 | 44 | 56 57 | 56 | 55 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 57 58 | 57 | 56 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 58 59 | 58 | 57 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 59 | | | | | | | | | | | | | 60 | 59 | 58 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 60 61 | 60 | 59 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 61 62 | 61 | 60 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 52 | 62 63 | 62 | 61 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 55 | 54 | 53 | 63 64 | 63 | 62 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 56 | 55 | 54 | 64 | | | | | | | | | | | | | 65 | 64 | 63 | 63 | 62 | 61 | 60 | 59 | 59 | 58 | 57 | 56 | 55 | 65 66 | 65 | 64 | 64 | 63 | 62 | 61 | 60 | 60 | 59 | 58 | 57 | 56 | 66 67 | 67 | 66 | 65 | 64 | 63 | 62 | 61 | 61 | 60 | 59 | 58 | 57 | 67 68 | 68 | 67 | 66 | 65 | 64 | 63 | 62 | 62 | 61 | 60 | 59 | 58 | 68 69 | 69 | 68 | 67 | 66 | 65 | 64 | 63 | 63 | 62 | 61 | 60 | 59 | 69 | | | | | | | | | | | | | 70 | 70 | 69 | 68 | 67 | 67 | 66 | 65 | 64 | 63 | 62 | 61 | 61 | 70 71 | 71 | 70 | 69 | 68 | 68 | 67 | 66 | 65 | 64 | 63 | 62 | 62 | 71 72 | 72 | 71 | 70 | 69 | 69 | 68 | 67 | 66 | 65 | 64 | 63 | 63 | 72 73 | 73 | 72 | 71 | 70 | 70 | 69 | 68 | 67 | 66 | 66 | 65 | 64 | 73 74 | 74 | 73 | 72 | 71 | 71 | 70 | 69 | 68 | 67 | 67 | 66 | 65 | 74 | | | | | | | | | | | | | 75 | 75 | 74 | 73 | 72 | 72 | 71 | 70 | 69 | 68 | 68 | 67 | 66 | 75 76 | 76 | 75 | 74 | 73 | 73 | 72 | 71 | 70 | 69 | 69 | 68 | 67 | 76 77 | 77 | 76 | 75 | 74 | 74 | 73 | 72 | 71 | 70 | 70 | 69 | 68 | 77 78 | 78 | 77 | 76 | 75 | 75 | 74 | 73 | 72 | 71 | 71 | 70 | 69 | 78 79 | 79 | 78 | 77 | 76 | 76 | 75 | 74 | 73 | 72 | 72 | 71 | 70 | 79 | | | | | | | | | | | | | 80 | 80 | 79 | 78 | 77 | 77 | 76 | 75 | 74 | 73 | 73 | 72 | 72 | 80 ------+----+----+----+----+----+----+----+----+----+----+----+----+------ _t._ |0°.5|1°.0|1°.5|2°.0|2°.5|3°.0|3°.5|4°.0|4°.5|5°.0|5°.5|6°.0| _t._ ======+====+====+====+====+====+====+====+====+====+====+====+====+======

TABLE I.——TEMPERATURE OF THE DEW-POINT, IN DEGREES FAHRENHEIT.

======+=============================================================================+====== _t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_ (Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ (Dry ther.)| 6°.0| 6°.5| 7°.0| 7°.5| 8°.0| 8°.5| 9°.0| 9°.5|10°.0|10°.5|11°.0|11°.5|12°.0|ther.) ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ 19 | -25 | | | | | | | | | | | | | 19 | | | | | | | | | | | | | | 20 | -19 | -32 | | | | | | | | | | | | 20 21 | -15 | -24 | -47 | | | | | | | | | | | 21 22 | -11 | -19 | -31 | | | | | | | | | | | 22 23 | -8 | -14 | -24 | -45 | | | | | | | | | | 23 24 | -5 | -10 | -18 | -30 | | | | | | | | | | 24 | | | | | | | | | | | | | | 25 | -2 | -7 | -13 | -22 | -42 | | | | | | | | | 25 26 | 0 | -4 | -9 | -17 | -28 | | | | | | | | | 26 27 | +3 | -1 | -6 | -12 | -20 | -37 | | | | | | | | 27 28 | 5 | +1 | -3 | -8 | -15 | -25 | -54 | | | | | | | 28 29 | 7 | 4 | 0 | -4 | -10 | -18 | -32 | | | | | | | 29 | | | | | | | | | | | | | | 30 | 9 | 6 | +2 | -2 | -6 | -13 | -22 | -43 | | | | | | 30 31 | 11 | 8 | 5 | +1 | -3 | -8 | -15 | -27 | | | | | | 31 32 | 13 | 10 | 7 | 4 | 0 | -4 | -10 | -18 | -33 | | | | | 32 33 | 14 | 12 | 9 | 6 | +3 | -1 | -6 | -12 | -22 | -44 | | | | 33 34 | 16 | 14 | 11 | 8 | 6 | +2 | -2 | -8 | -15 | -27 | | | | 34 | | | | | | | | | | | | | | 35 | 18 | 15 | 13 | 10 | 8 | 5 | +1 | -4 | -9 | -18 | -32 | | | 35 36 | 19 | 17 | 15 | 12 | 10 | 8 | 4 | 0 | -5 | -12 | -20 | -42 | | 36 37 | 21 | 19 | 17 | 14 | 12 | 9 | 6 | +3 | -2 | -6 | -14 | -25 | -52 | 37 38 | 22 | 20 | 19 | 16 | 14 | 11 | 9 | 6 | +2 | -2 | -8 | -16 | -29 | 38 39 | 24 | 22 | 20 | 18 | 16 | 14 | 11 | 8 | 5 | +1 | -4 | -10 | -18 | 39 | | | | | | | | | | | | | | 40 | 25 | 23 | 22 | 20 | 18 | 16 | 13 | 11 | 8 | 4 | 0 | -5 | -12 | 40 41 | 26 | 25 | 23 | 21 | 20 | 17 | 15 | 13 | 10 | 7 | +4 | -1 | -6 | 41 42 | 27 | 26 | 24 | 23 | 21 | 19 | 18 | 15 | 12 | 10 | 7 | +3 | -2 | 42 43 | 29 | 27 | 26 | 24 | 23 | 21 | 19 | 17 | 14 | 12 | 9 | 6 | +2 | 43 44 | 30 | 28 | 27 | 26 | 24 | 22 | 20 | 18 | 16 | 14 | 12 | 9 | 6 | 44 | | | | | | | | | | | | | | 45 | 31 | 30 | 28 | 27 | 25 | 24 | 22 | 20 | 18 | 16 | 13 | 11 | 8 | 45 46 | 32 | 31 | 30 | 28 | 27 | 25 | 24 | 22 | 20 | 18 | 16 | 13 | 11 | 46 47 | 33 | 32 | 31 | 29 | 28 | 26 | 25 | 23 | 22 | 20 | 18 | 15 | 13 | 47 48 | 35 | 33 | 32 | 30 | 29 | 28 | 26 | 25 | 23 | 21 | 20 | 17 | 15 | 48 49 | 36 | 34 | 33 | 32 | 31 | 29 | 28 | 26 | 25 | 23 | 21 | 19 | 17 | 49 | | | | | | | | | | | | | | 50 | 37 | 35 | 34 | 33 | 32 | 31 | 29 | 28 | 26 | 24 | 23 | 21 | 19 | 50 51 | 38 | 37 | 36 | 34 | 33 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 21 | 51 52 | 40 | 38 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 28 | 26 | 24 | 23 | 52 53 | 41 | 39 | 38 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 28 | 26 | 24 | 53 54 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 27 | 26 | 54 | | | | | | | | | | | | | | 55 | 43 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 28 | 55 56 | 44 | 43 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 56 57 | 46 | 45 | 44 | 42 | 41 | 40 | 39 | 37 | 36 | 35 | 33 | 32 | 30 | 57 58 | 47 | 46 | 45 | 44 | 42 | 41 | 40 | 39 | 37 | 36 | 35 | 33 | 32 | 58 59 | 48 | 47 | 46 | 45 | 44 | 43 | 41 | 40 | 39 | 38 | 36 | 35 | 33 | 59 | | | | | | | | | | | | | | 60 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 41 | 40 | 39 | 38 | 36 | 35 | 60 61 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 39 | 38 | 36 | 61 62 | 52 | 51 | 50 | 49 | 48 | 47 | 45 | 44 | 43 | 42 | 41 | 39 | 38 | 62 63 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 45 | 44 | 43 | 42 | 41 | 39 | 63 64 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 43 | 42 | 41 | 64 | | | | | | | | | | | | | | 65 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 43 | 42 | 65 66 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 66 67 | 57 | 56 | 55 | 55 | 54 | 53 | 52 | 51 | 50 | 48 | 47 | 46 | 45 | 67 68 | 58 | 57 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 47 | 46 | 68 69 | 59 | 58 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 69 | | | | | | | | | | | | | | 70 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 70 71 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 55 | 54 | 53 | 52 | 51 | 71 72 | 63 | 62 | 61 | 60 | 59 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 72 73 | 64 | 63 | 62 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 73 74 | 65 | 64 | 63 | 63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 74 | | | | | | | | | | | | | | 75 | 66 | 65 | 64 | 64 | 63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 56 | 75 76 | 67 | 66 | 65 | 65 | 64 | 63 | 62 | 61 | 61 | 60 | 59 | 58 | 57 | 76 77 | 68 | 67 | 67 | 66 | 65 | 64 | 63 | 62 | 62 | 61 | 60 | 59 | 58 | 77 78 | 69 | 68 | 68 | 67 | 66 | 66 | 65 | 64 | 63 | 62 | 61 | 60 | 59 | 78 79 | 70 | 69 | 69 | 68 | 67 | 67 | 66 | 65 | 64 | 63 | 62 | 61 | 61 | 79 | | | | | | | | | | | | | | 80 | 72 | 71 | 70 | 69 | 68 | 68 | 67 | 66 | 65 | 64 | 63 | 62 | 62 | 80 ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ _t._ | 6°.0| 6°.5| 7°.0| 7°.5| 8°.0| 8°.5| 9°.0| 9°.5|10°.0|10°.5|11°.0|11°.5|12°.0| _t._ ======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======

TABLE I.——TEMPERATURE OF THE DEW-POINT, IN DEGREES FAHRENHEIT.

======+=============================================================================+====== _t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_ (Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+(Dry ther.)|12°.0|12°.5|13°.0|13°.5|14°.0|14°.5|15°.0|15°.5|16°.0|16°.5|17°.0|17°.5|18°.0|ther.) ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ 40 | -12 | -22 | -44 | | | | | | | | | | | 40 41 | -6 | -13 | -25 | | | | | | | | | | | 41 42 | -2 | -7 | -15 | -28 | | | | | | | | | | 42 43 | +2 | -3 | -8 | -17 | -33 | | | | | | | | | 43 44 | 6 | +1 | -4 | -10 | -19 | -40 | | | | | | | | 44 | | | | | | | | | | | | | | 45 | 8 | 5 | 0 | -4 | -11 | -22 | -48 | | | | | | | 45 46 | 11 | 8 | +4 | 0 | -5 | -13 | -24 | | | | | | | 46 47 | 13 | 10 | 7 | +3 | -1 | -6 | -14 | -27 | | | | | | 47 48 | 15 | 12 | 10 | 6 | +2 | -2 | -8 | -16 | -30 | | | | | 48 49 | 17 | 14 | 12 | 9 | 6 | +2 | -3 | -9 | -18 | -35 | | | | 49 | | | | | | | | | | | | | | 50 | 19 | 16 | 14 | 12 | 9 | 5 | +1 | -4 | -10 | -20 | -42 | | | 50 51 | 21 | 18 | 17 | 14 | 11 | 8 | 5 | 0 | -5 | -12 | -22 | -52 | | 51 52 | 23 | 21 | 19 | 16 | 14 | 11 | 8 | +4 | 0 | -6 | -13 | -25 | | 52 53 | 24 | 22 | 20 | 18 | 16 | 14 | 11 | 8 | +4 | -1 | -6 | -14 | -28 | 53 54 | 26 | 24 | 22 | 20 | 18 | 16 | 13 | 10 | 7 | +3 | -2 | -8 | -16 | 54 | | | | | | | | | | | | | | 55 | 28 | 26 | 24 | 22 | 20 | 18 | 16 | 13 | 10 | 7 | +3 | -2 | -8 | 55 56 | 29 | 27 | 26 | 24 | 22 | 20 | 18 | 15 | 13 | 10 | 6 | +2 | -2 | 56 57 | 30 | 29 | 28 | 26 | 24 | 22 | 20 | 18 | 15 | 13 | 10 | 6 | +2 | 57 58 | 32 | 30 | 29 | 27 | 26 | 24 | 22 | 20 | 18 | 15 | 12 | 9 | 6 | 58 59 | 33 | 32 | 31 | 29 | 27 | 26 | 24 | 22 | 20 | 18 | 15 | 12 | 9 | 59 | | | | | | | | | | | | | | 60 | 35 | 33 | 32 | 30 | 29 | 27 | 26 | 24 | 22 | 20 | 18 | 15 | 12 | 60 61 | 36 | 35 | 33 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 20 | 18 | 15 | 61 62 | 38 | 37 | 35 | 34 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 20 | 18 | 62 63 | 39 | 38 | 37 | 35 | 34 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 20 | 63 64 | 41 | 39 | 38 | 37 | 35 | 34 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 64 | | | | | | | | | | | | | | 65 | 42 | 41 | 40 | 38 | 37 | 35 | 34 | 32 | 31 | 29 | 28 | 26 | 24 | 65 66 | 44 | 43 | 41 | 40 | 38 | 37 | 35 | 34 | 32 | 31 | 30 | 28 | 26 | 66 67 | 45 | 44 | 43 | 41 | 40 | 39 | 37 | 36 | 34 | 32 | 31 | 30 | 28 | 67 68 | 46 | 45 | 44 | 43 | 42 | 40 | 39 | 38 | 36 | 34 | 33 | 31 | 30 | 68 69 | 48 | 47 | 46 | 45 | 43 | 42 | 40 | 39 | 38 | 36 | 34 | 33 | 32 | 69 | | | | | | | | | | | | | | 70 | 49 | 48 | 47 | 46 | 45 | 43 | 42 | 41 | 39 | 38 | 36 | 35 | 33 | 70 71 | 51 | 49 | 48 | 47 | 46 | 45 | 43 | 42 | 41 | 39 | 38 | 36 | 35 | 71 72 | 52 | 51 | 50 | 49 | 47 | 46 | 45 | 44 | 43 | 41 | 40 | 38 | 37 | 72 73 | 53 | 52 | 51 | 50 | 49 | 48 | 46 | 45 | 44 | 43 | 41 | 40 | 38 | 73 74 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 45 | 44 | 43 | 41 | 40 | 74 | | | | | | | | | | | | | | 75 | 56 | 55 | 54 | 53 | 52 | 50 | 49 | 48 | 47 | 45 | 44 | 43 | 42 | 75 76 | 57 | 56 | 55 | 54 | 53 | 52 | 50 | 49 | 48 | 47 | 46 | 45 | 43 | 76 77 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 46 | 45 | 77 78 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 78 79 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 49 | 48 | 79 | | | | | | | | | | | | | | 80 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 80 ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ _t._ |12°.0|12°.5|13°.0|13°.5|14°.0|14°.5|15°.0|15°.5|16°.0|16°.5|17°.0|17°.5|18°.0| _t._ ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------

TABLE I.——TEMPERATURE OF THE DEW-POINT, IN DEGREES FAHRENHEIT.

======+==============================================================+====== _t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_ (Dry +----+----+----+----+----+----+----+----+----+-----+-----+-----+(Dry ther.)|1°.0|2°.0|3°.0|4°.0|5°.0|6°.0|7°.0|8°.0|9°.0|10°.0|11°.0|12°.0|ther.) ------+----+----+----+----+----+----+----+----+----+-----+-----+-----+------ 80 | 79 | 77 | 76 | 74 | 73 | 72 | 70 | 68 | 67 | 65 | 63 | 62 | 80 81 | 80 | 78 | 77 | 75 | 74 | 73 | 71 | 70 | 68 | 66 | 65 | 63 | 81 82 | 81 | 79 | 78 | 77 | 75 | 74 | 72 | 71 | 69 | 68 | 66 | 64 | 82 83 | 82 | 80 | 79 | 78 | 76 | 75 | 73 | 72 | 70 | 69 | 67 | 65 | 83 84 | 83 | 81 | 80 | 79 | 77 | 76 | 74 | 73 | 71 | 70 | 68 | 67 | 84 | | | | | | | | | | | | | 85 | 84 | 82 | 81 | 80 | 78 | 77 | 75 | 74 | 72 | 71 | 69 | 68 | 85 86 | 85 | 83 | 82 | 81 | 79 | 78 | 76 | 75 | 73 | 72 | 71 | 69 | 86 87 | 86 | 84 | 83 | 82 | 80 | 79 | 78 | 76 | 74 | 73 | 72 | 70 | 87 88 | 87 | 85 | 84 | 83 | 81 | 80 | 79 | 77 | 75 | 74 | 73 | 71 | 88 89 | 88 | 86 | 85 | 84 | 82 | 81 | 80 | 78 | 76 | 76 | 74 | 72 | 89 | | | | | | | | | | | | | 90 | 89 | 87 | 86 | 85 | 84 | 82 | 81 | 79 | 78 | 77 | 75 | 74 | 90 91 | 90 | 88 | 87 | 86 | 85 | 83 | 82 | 80 | 79 | 78 | 76 | 75 | 91 92 | 91 | 89 | 88 | 87 | 86 | 84 | 83 | 82 | 80 | 79 | 77 | 76 | 92 93 | 92 | 91 | 89 | 88 | 87 | 85 | 84 | 83 | 81 | 80 | 78 | 77 | 93 94 | 93 | 92 | 90 | 89 | 88 | 86 | 85 | 84 | 82 | 81 | 80 | 78 | 94 | | | | | | | | | | | | | 95 | 94 | 93 | 91 | 90 | 89 | 87 | 86 | 85 | 83 | 82 | 81 | 79 | 95 96 | 95 | 94 | 92 | 91 | 90 | 88 | 87 | 86 | 84 | 83 | 82 | 80 | 96 97 | 96 | 95 | 93 | 92 | 91 | 90 | 88 | 87 | 86 | 84 | 83 | 81 | 97 98 | 97 | 96 | 94 | 93 | 92 | 91 | 89 | 88 | 87 | 85 | 84 | 83 | 98 99 | 98 | 97 | 95 | 94 | 93 | 92 | 90 | 89 | 88 | 86 | 85 | 84 | 99 | | | | | | | | | | | | | 100 | 99 | 98 | 96 | 95 | 94 | 93 | 91 | 90 | 89 | 87 | 86 | 85 | 100 101 |100 | 99 | 97 | 96 | 95 | 94 | 92 | 91 | 90 | 88 | 87 | 86 | 101 102 |101 |100 | 98 | 97 | 96 | 95 | 93 | 92 | 91 | 90 | 88 | 87 | 102 103 |102 |101 | 99 | 98 | 97 | 96 | 94 | 93 | 92 | 91 | 89 | 88 | 103 104 |103 |102 |100 | 99 | 98 | 97 | 96 | 94 | 93 | 92 | 90 | 89 | 104 | | | | | | | | | | | | | 105 |104 |103 |101 |100 | 99 | 98 | 97 | 95 | 94 | 93 | 91 | 90 | 105 106 |105 |104 |102 |101 |100 | 99 | 98 | 96 | 95 | 94 | 93 | 91 | 106 107 |106 |105 |103 |102 |101 |100 | 99 | 97 | 96 | 95 | 94 | 92 | 107 108 |107 |106 |104 |103 |102 |101 |100 | 98 | 97 | 96 | 95 | 93 | 108 109 |108 |107 |105 |104 |103 |102 |101 | 99 | 98 | 97 | 96 | 94 | 109 | | | | | | | | | | | | | 110 |109 |108 |107 |105 |104 |103 |102 |101 | 99 | 98 | 97 | 96 | 110 ------+----+----+----+----+----+----+----+----+----+-----+-----+-----+------ _t._ |1°.0|2°.0|3°.0|4°.0|5°.0|6°.0|7°.0|8°.0|9°.0|10°.0|11°.0|12°.0| _t._ ======+====+====+====+====+====+====+====+====+====+=====+=====+=====+======

TABLE I.——TEMPERATURE OF THE DEW-POINT, IN DEGREES FAHRENHEIT.

TABLE II.——RELATIVE HUMIDITY, PER CENT.

======+================================================================+======= _t_ | Difference between the dry and wet thermometers (_t_——_t′_). | _t_ (Dry +----+----+----+----+----+----+----+----+----+----+----+----+----+ (Dry ther.)|0°.2|0°.4|0°.6|0°.8|1°.0|1°.2|1°.4|1°.6|1°.8|2°.0|2°.2|2°.4|2°.6| ther.) ------+----+----+----+----+----+----+----+----+----+----+----+----+----+------- -40 | 46 | | | | | | | | | | | | | -40 -39 | 49 | | | | | | | | | | | | | -39 -38 | 51 | | | | | | | | | | | | | -38 -37 | 54 | | | | | | | | | | | | | -37 -36 | 56 | | | | | | | | | | | | | -36 | | | | | | | | | | | | | | -35 | 59 | | | | | | | | | | | | | -35 -34 | 61 | 22 | | | | | | | | | | | | -34 -33 | 63 | 25 | | | | | | | | | | | | -33 -32 | 65 | 30 | | | | | | | | | | | | -32 -31 | 67 | 34 | | | | | | | | | | | | -31 | | | | | | | | | | | | | | -30 | 69 | 38 | | | | | | | | | | | | -30 -29 | 71 | 42 | | | | | | | | | | | | -29 -28 | 72 | 45 | 17 | | | | | | | | | | | -28 -27 | 74 | 48 | 22 | | | | | | | | | | | -27 -26 | 76 | 51 | 26 | | | | | | | | | | | -26 | | | | | | | | | | | | | | -25 | 77 | 53 | 31 | | | | | | | | | | | -25 -24 | 78 | 56 | 34 | 12 | | | | | | | | | | -24 -23 | 79 | 58 | 37 | 16 | | | | | | | | | | -23 -22 | 80 | 60 | 40 | 20 | | | | | | | | | | -22 -21 | 81 | 62 | 44 | 25 | | | | | | | | | | -21 | | | | | | | | | | | | | | -20 | 82 | 64 | 47 | 29 | 11 | | | | | | | | | -20 -19 | 83 | 66 | 49 | 33 | 16 | | | | | | | | | -19 -18 | 84 | 68 | 52 | 36 | 20 | | | | | | | | | -18 -17 | 85 | 70 | 54 | 39 | 24 | 9 | | | | | | | | -17 -16 | 86 | 71 | 57 | 43 | 28 | 14 | | | | | | | | -16 | | | | | | | | | | | | | | -15 | 86 | 73 | 59 | 46 | 32 | 19 | | | | | | | | -15 -14 | 87 | 74 | 61 | 48 | 36 | 23 | 10 | | | | | | | -14 -13 | 88 | 76 | 63 | 51 | 39 | 27 | 15 | | | | | | | -13 -12 | 88 | 77 | 65 | 53 | 42 | 30 | 19 | 7 | | | | | | -12 -11 | 89 | 78 | 67 | 56 | 45 | 34 | 23 | 12 | | | | | | -11 | | | | | | | | | | | | | | -10 | 90 | 79 | 68 | 58 | 48 | 37 | 26 | 16 | 5 | | | | | -10 -9 | 90 | 80 | 70 | 60 | 50 | 40 | 30 | 20 | 10 | | | | | -9 -8 | 90 | 81 | 71 | 62 | 52 | 43 | 33 | 24 | 14 | 5 | | | | -8 -7 | 91 | 82 | 73 | 63 | 54 | 45 | 36 | 27 | 18 | 9 | | | | -7 -6 | 91 | 83 | 74 | 65 | 56 | 48 | 39 | 31 | 22 | 13 | 5 | | | -6 | | | | | | | | | | | | | | -5 | 92 | 83 | 75 | 67 | 58 | 50 | 42 | 34 | 25 | 17 | 9 | | | -5 -4 | 92 | 84 | 76 | 68 | 60 | 52 | 45 | 37 | 29 | 21 | 13 | 5 | | -4 -3 | 92 | 85 | 77 | 70 | 62 | 55 | 47 | 40 | 32 | 25 | 17 | 10 | | -3 -2 | 93 | 86 | 78 | 71 | 64 | 57 | 50 | 42 | 35 | 28 | 21 | 14 | 7 | -2 -1 | 93 | 86 | 79 | 72 | 66 | 59 | 52 | 45 | 38 | 31 | 25 | 18 | 11 | -1 | | | | | | | | | | | | | | 0 | 93 | 87 | 80 | 74 | 67 | 61 | 54 | 48 | 41 | 35 | 28 | 22 | 15 | 0 +1 | 94 | 87 | 81 | 75 | 69 | 63 | 56 | 50 | 44 | 38 | 32 | 25 | 19 | +1 2 | 94 | 88 | 82 | 76 | 70 | 64 | 58 | 52 | 46 | 40 | 35 | 29 | 23 | 2 3 | 94 | 88 | 83 | 77 | 71 | 66 | 60 | 54 | 49 | 43 | 37 | 32 | 26 | 3 4 | 94 | 89 | 83 | 78 | 73 | 67 | 62 | 56 | 51 | 45 | 40 | 34 | 29 | 4 | | | | | | | | | | | | | | 5 | 95 | 89 | 84 | 79 | 74 | 68 | 63 | 58 | 53 | 48 | 42 | 37 | 32 | 5 6 | 95 | 90 | 85 | 80 | 75 | 70 | 65 | 60 | 54 | 50 | 44 | 39 | 34 | 6 7 | 95 | 90 | 85 | 80 | 76 | 71 | 66 | 61 | 56 | 51 | 47 | 42 | 37 | 7 8 | 95 | 91 | 86 | 81 | 76 | 72 | 67 | 62 | 58 | 53 | 49 | 44 | 39 | 8 9 | 96 | 91 | 86 | 82 | 77 | 73 | 68 | 64 | 59 | 55 | 51 | 46 | 42 | 9 | | | | | | | | | | | | | | 10 | 96 | 91 | 87 | 83 | 78 | 74 | 69 | 65 | 61 | 57 | 52 | 48 | 44 | 10 11 | 96 | 92 | 87 | 83 | 79 | 75 | 71 | 66 | 62 | 58 | 54 | 50 | 46 | 11 12 | 96 | 92 | 88 | 84 | 80 | 76 | 72 | 68 | 64 | 60 | 56 | 52 | 48 | 12 13 | 96 | 92 | 88 | 84 | 81 | 77 | 73 | 69 | 65 | 61 | 58 | 54 | 50 | 13 14 | 96 | 93 | 89 | 85 | 81 | 78 | 74 | 70 | 67 | 63 | 59 | 56 | 52 | 14 | | | | | | | | | | | | | | 15 | 96 | 93 | 89 | 86 | 82 | 79 | 75 | 71 | 68 | 64 | 61 | 57 | 54 | 15 16 | 97 | 93 | 90 | 86 | 83 | 79 | 76 | 73 | 69 | 66 | 62 | 59 | 56 | 16 17 | 97 | 93 | 90 | 87 | 83 | 80 | 77 | 74 | 70 | 67 | 64 | 60 | 57 | 17 18 | 97 | 94 | 90 | 87 | 84 | 81 | 78 | 74 | 71 | 68 | 65 | 62 | 59 | 18 19 | 97 | 94 | 91 | 88 | 84 | 81 | 78 | 75 | 72 | 69 | 66 | 63 | 60 | 19 | | | | | | | | | | | | | | 20 | 97 | 94 | 91 | 88 | 85 | 82 | 79 | 76 | 73 | 70 | 67 | 64 | 61 | 20 ------+----+----+----+----+----+----+----+----+----+----+----+----+----+------- _t._ |0°.2|0°.4|0°.6|0°.8|1°.0|1°.2|1°.4|1°.6|1°.8|2°.0|2°.2|2°.4|2°.6| _t._ ======+====+====+====+====+====+====+====+====+====+====+====+====+====+=======

TABLE II.——RELATIVE HUMIDITY, PER CENT.

======+===========================================================+====== _t_ | Difference between the dry and wet thermometers (_t-t′_).| _t_ (Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+(Dry ther.)| 2°.6| 2°.8| 3°.0| 3°.2| 3°.4| 3°.6| 3°.8| 4°.0| 4°.2| 4°.4|ther.) ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ -2 | 7 | | | | | | | | | | -2 -1 | 11 | 4 | | | | | | | | | -1 | | | | | | | | | | | 0 | 15 | 9 | | | | | | | | | 0 +1 | 19 | 13 | 7 | | | | | | | | +1 2 | 23 | 17 | 11 | 5 | | | | | | | 2 3 | 26 | 20 | 15 | 9 | 4 | | | | | | 3 4 | 29 | 24 | 18 | 13 | 8 | 2 | | | | | 4 | | | | | | | | | | | 5 | 32 | 27 | 22 | 16 | 11 | 6 | | | | | 5 6 | 34 | 29 | 25 | 20 | 15 | 10 | 5 | | | | 6 7 | 37 | 32 | 28 | 23 | 18 | 13 | 9 | 4 | | | 7 8 | 39 | 35 | 30 | 26 | 21 | 17 | 12 | 8 | 3 | | 8 9 | 42 | 37 | 33 | 28 | 24 | 20 | 15 | 11 | 7 | 2 | 9 | | | | | | | | | | | 10 | 44 | 40 | 35 | 31 | 27 | 23 | 19 | 14 | 10 | 6 | 10 11 | 46 | 42 | 38 | 34 | 30 | 26 | 22 | 18 | 14 | 10 | 11 12 | 48 | 44 | 40 | 36 | 32 | 28 | 25 | 21 | 17 | 13 | 12 13 | 50 | 46 | 42 | 39 | 35 | 31 | 27 | 24 | 20 | 16 | 13 14 | 52 | 48 | 45 | 41 | 37 | 34 | 30 | 27 | 23 | 19 | 14 | | | | | | | | | | | 15 | 54 | 50 | 47 | 43 | 40 | 36 | 33 | 29 | 26 | 23 | 15 16 | 56 | 52 | 49 | 46 | 42 | 39 | 36 | 32 | 29 | 25 | 16 17 | 57 | 54 | 51 | 48 | 44 | 41 | 38 | 35 | 31 | 28 | 17 18 | 59 | 56 | 53 | 49 | 46 | 43 | 40 | 37 | 34 | 31 | 18 19 | 60 | 57 | 54 | 51 | 48 | 45 | 42 | 39 | 36 | 33 | 19 | | | | | | | | | | | 20 | 61 | 58 | 56 | 53 | 50 | 47 | 44 | 41 | 38 | 35 | 20 ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ _t._ | 2°.6| 2°.8| 3°.0| 3°.2| 3°.4| 3°.6| 3°.8| 4°.0| 4°.2| 4°.4| _t._ ======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======

======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+====== _t._ | 4°.6| 4°.8| 5°.0| 5°.2| 5°.4| 5°.6| 5°.8| 6°.0| 6°.2| 6°.4| _t._ ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ 8 | | | | | | | | | | | 8 9 | | | | | | | | | | | 9 | | | | | | | | | | | 10 | 2 | | | | | | | | | | 10 11 | 6 | 2 | | | | | | | | | 11 12 | 9 | 5 | 2 | | | | | | | | 12 13 | 13 | 9 | 5 | 2 | | | | | | | 13 14 | 16 | 12 | 9 | 5 | 2 | | | | | | 14 | | | | | | | | | | | 15 | 19 | 16 | 12 | 9 | 5 | 2 | | | | | 15 16 | 22 | 19 | 16 | 12 | 9 | 6 | 2 | | | | 16 17 | 25 | 22 | 19 | 16 | 12 | 9 | 6 | 3 | | | 17 18 | 28 | 25 | 22 | 19 | 16 | 13 | 9 | 6 | 3 | | 18 19 | 30 | 27 | 24 | 21 | 19 | 16 | 13 | 10 | 7 | 4 | 19 | | | | | | | | | | | 20 | 33 | 30 | 27 | 24 | 21 | 19 | 16 | 13 | 10 | 7 | 20 ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ _t._ | 4°.6| 4°.8| 5°.0| 5°.2| 5°.4| 5°.6| 5°.8| 6°.0| 6°.2| 6°.4| _t._ ======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======

TABLE II.——RELATIVE HUMIDITY, PER CENT.

======+=======================================================================+====== _t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_ (Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+(Dry ther.)| 0°.5| 1°.0| 1°.5| 2°.0| 2°.5| 3°.0| 3°.5| 4°.0| 4°.5| 5°.0| 5°.5| 6°.0|ther.) ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ 20 | 92 | 85 | 77 | 70 | 63 | 56 | 48 | 41 | 34 | 27 | 20 | 13 | 20 21 | 93 | 85 | 78 | 71 | 64 | 57 | 50 | 43 | 36 | 29 | 23 | 16 | 21 22 | 93 | 86 | 79 | 72 | 65 | 58 | 51 | 45 | 38 | 32 | 25 | 19 | 22 23 | 93 | 86 | 80 | 73 | 66 | 60 | 53 | 46 | 40 | 34 | 27 | 21 | 23 24 | 93 | 87 | 80 | 74 | 67 | 61 | 54 | 48 | 42 | 36 | 30 | 24 | 24 | | | | | | | | | | | | | 25 | 94 | 87 | 81 | 74 | 68 | 62 | 56 | 50 | 44 | 38 | 32 | 26 | 25 26 | 94 | 88 | 81 | 75 | 69 | 63 | 57 | 51 | 45 | 40 | 34 | 28 | 26 27 | 94 | 88 | 82 | 76 | 70 | 64 | 59 | 53 | 47 | 42 | 36 | 30 | 27 28 | 94 | 88 | 82 | 77 | 71 | 65 | 60 | 54 | 49 | 43 | 38 | 33 | 28 29 | 94 | 89 | 83 | 77 | 72 | 66 | 61 | 56 | 50 | 45 | 40 | 35 | 29 | | | | | | | | | | | | | 30 | 94 | 89 | 84 | 78 | 73 | 67 | 62 | 57 | 52 | 47 | 41 | 36 | 30 31 | 95 | 89 | 84 | 79 | 74 | 68 | 63 | 58 | 53 | 48 | 43 | 38 | 31 32 | 95 | 90 | 84 | 79 | 74 | 69 | 64 | 59 | 54 | 50 | 45 | 40 | 32 33 | 95 | 90 | 85 | 80 | 75 | 70 | 65 | 60 | 56 | 51 | 47 | 42 | 33 34 | 95 | 91 | 86 | 81 | 75 | 72 | 67 | 62 | 57 | 53 | 48 | 44 | 34 | | | | | | | | | | | | | 35 | 95 | 91 | 86 | 82 | 76 | 73 | 69 | 65 | 59 | 54 | 50 | 45 | 35 36 | 96 | 91 | 86 | 82 | 77 | 73 | 70 | 66 | 61 | 56 | 51 | 47 | 36 37 | 96 | 91 | 87 | 82 | 78 | 74 | 70 | 66 | 62 | 57 | 52 | 48 | 37 38 | 96 | 92 | 87 | 83 | 79 | 75 | 71 | 67 | 63 | 58 | 54 | 50 | 38 39 | 96 | 92 | 88 | 83 | 79 | 75 | 72 | 68 | 63 | 59 | 55 | 52 | 39 | | | | | | | | | | | | | 40 | 96 | 92 | 88 | 84 | 80 | 76 | 72 | 68 | 64 | 60 | 56 | 53 | 40 41 | 96 | 92 | 88 | 84 | 80 | 76 | 72 | 69 | 65 | 61 | 57 | 54 | 41 42 | 96 | 92 | 88 | 84 | 81 | 77 | 73 | 69 | 65 | 62 | 58 | 55 | 42 43 | 96 | 92 | 88 | 85 | 81 | 77 | 74 | 70 | 66 | 63 | 59 | 56 | 43 44 | 96 | 92 | 88 | 85 | 81 | 78 | 74 | 70 | 67 | 63 | 60 | 57 | 44 | | | | | | | | | | | | | 45 | 96 | 92 | 89 | 85 | 82 | 78 | 75 | 71 | 67 | 64 | 61 | 58 | 45 46 | 96 | 93 | 89 | 85 | 82 | 79 | 75 | 72 | 68 | 65 | 61 | 58 | 46 47 | 96 | 93 | 89 | 86 | 83 | 79 | 76 | 72 | 69 | 66 | 62 | 59 | 47 48 | 96 | 93 | 89 | 86 | 83 | 79 | 76 | 73 | 69 | 66 | 63 | 60 | 48 49 | 97 | 93 | 90 | 86 | 83 | 80 | 76 | 73 | 70 | 67 | 63 | 60 | 49 | | | | | | | | | | | | | 50 | 97 | 93 | 90 | 87 | 83 | 80 | 77 | 74 | 70 | 67 | 64 | 61 | 50 51 | 97 | 93 | 90 | 87 | 84 | 81 | 77 | 74 | 71 | 68 | 65 | 62 | 51 52 | 97 | 94 | 90 | 87 | 84 | 81 | 78 | 75 | 72 | 69 | 66 | 63 | 52 53 | 97 | 94 | 91 | 87 | 84 | 81 | 78 | 75 | 72 | 69 | 66 | 63 | 53 54 | 97 | 94 | 91 | 88 | 85 | 82 | 79 | 76 | 73 | 70 | 67 | 64 | 54 | | | | | | | | | | | | | 55 | 97 | 94 | 91 | 88 | 85 | 82 | 79 | 76 | 73 | 70 | 68 | 65 | 55 56 | 97 | 94 | 91 | 88 | 85 | 82 | 80 | 77 | 74 | 71 | 68 | 65 | 56 57 | 97 | 94 | 91 | 88 | 86 | 83 | 80 | 77 | 74 | 71 | 69 | 66 | 57 58 | 97 | 94 | 91 | 89 | 86 | 83 | 80 | 78 | 75 | 72 | 69 | 67 | 58 59 | 97 | 94 | 92 | 89 | 86 | 83 | 81 | 78 | 75 | 72 | 70 | 67 | 59 | | | | | | | | | | | | | 60 | 97 | 94 | 92 | 89 | 86 | 84 | 81 | 78 | 75 | 73 | 70 | 68 | 60 61 | 97 | 94 | 92 | 89 | 87 | 84 | 81 | 78 | 76 | 73 | 71 | 68 | 61 62 | 97 | 95 | 92 | 89 | 87 | 84 | 81 | 79 | 76 | 74 | 71 | 69 | 62 63 | 97 | 95 | 92 | 89 | 87 | 84 | 82 | 79 | 77 | 74 | 72 | 69 | 63 64 | 97 | 95 | 92 | 90 | 87 | 85 | 82 | 79 | 77 | 74 | 72 | 70 | 64 | | | | | | | | | | | | | 65 | 97 | 95 | 92 | 90 | 87 | 85 | 82 | 80 | 77 | 75 | 72 | 70 | 65 66 | 97 | 95 | 92 | 90 | 87 | 85 | 82 | 80 | 78 | 75 | 73 | 71 | 66 67 | 98 | 95 | 93 | 90 | 88 | 85 | 83 | 80 | 78 | 76 | 73 | 71 | 67 68 | 98 | 95 | 93 | 90 | 88 | 85 | 83 | 81 | 78 | 76 | 74 | 71 | 68 69 | 98 | 95 | 93 | 90 | 88 | 86 | 83 | 81 | 78 | 76 | 74 | 72 | 69 | | | | | | | | | | | | | 70 | 98 | 95 | 93 | 90 | 88 | 86 | 83 | 81 | 79 | 77 | 74 | 72 | 70 71 | 98 | 95 | 93 | 91 | 88 | 86 | 84 | 81 | 79 | 77 | 75 | 72 | 71 72 | 98 | 95 | 93 | 91 | 88 | 86 | 84 | 82 | 79 | 77 | 75 | 73 | 72 73 | 98 | 95 | 93 | 91 | 88 | 86 | 84 | 82 | 80 | 78 | 75 | 73 | 73 74 | 98 | 95 | 93 | 91 | 88 | 86 | 84 | 82 | 80 | 78 | 76 | 74 | 74 | | | | | | | | | | | | | 75 | 98 | 95 | 93 | 91 | 89 | 87 | 84 | 82 | 80 | 78 | 76 | 74 | 75 76 | 98 | 95 | 93 | 91 | 89 | 87 | 85 | 82 | 80 | 78 | 76 | 74 | 76 77 | 98 | 95 | 93 | 91 | 89 | 87 | 85 | 83 | 80 | 78 | 76 | 74 | 77 78 | 98 | 96 | 93 | 91 | 89 | 87 | 85 | 83 | 81 | 79 | 77 | 75 | 78 79 | 98 | 96 | 94 | 91 | 89 | 87 | 85 | 83 | 81 | 79 | 77 | 75 | 79 | | | | | | | | | | | | | 80 | 98 | 96 | 94 | 92 | 89 | 87 | 85 | 83 | 81 | 79 | 77 | 75 | 80 ------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------ _t._ | 0°.5| 1°.0| 1°.5| 2°.0| 2°.5| 3°.0| 3°.5| 4°.0| 4°.5| 5°.0| 5°.5| 6°.0| _t._ ======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======

TABLE II.——RELATIVE HUMIDITY, PER CENT.

======+=====================================================================+===== _t_ | Difference between the dry and wet thermometers (_t-t′_). |_t_ (Dry +----+----+----+----+----+----+----+----+-----+-----+-----+-----+-----+(Dry ther.)|6°.0|6°.5|7°.0|7°.5|8°.0|8°.5|9°.0|9°.5|10°.0|10°.5|11°.0|11°.5|12°.0|ther.) ------+----+----+----+----+----+----+----+----+-----+-----+-----+-----+-----+------ 19 | 10 | | | | | | | | | | | | | 19 | | | | | | | | | | | | | | 20 | 13 | 6 | | | | | | | | | | | | 20 21 | 16 | 9 | 2 | | | | | | | | | | | 21 22 | 19 | 12 | 6 | | | | | | | | | | | 22 23 | 21 | 15 | 9 | 2 | | | | | | | | | | 23 24 | 24 | 17 | 11 | 6 | | | | | | | | | | 24 | | | | | | | | | | | | | | 25 | 26 | 20 | 14 | 8 | 3 | | | | | | | | | 25 26 | 28 | 23 | 17 | 11 | 6 | | | | | | | | | 26 27 | 30 | 25 | 19 | 14 | 9 | 3 | | | | | | | | 27 28 | 33 | 27 | 22 | 17 | 11 | 6 | 1 | | | | | | | 28 29 | 35 | 29 | 24 | 19 | 14 | 9 | 4 | | | | | | | 29 | | | | | | | | | | | | | | 30 | 36 | 31 | 26 | 22 | 17 | 12 | 7 | 2 | | | | | | 30 31 | 38 | 33 | 29 | 24 | 19 | 14 | 10 | 5 | | | | | | 31 32 | 40 | 35 | 31 | 26 | 21 | 17 | 12 | 8 | 3 | | | | | 32 33 | 42 | 37 | 33 | 28 | 24 | 19 | 15 | 10 | 6 | 2 | | | | 33 34 | 44 | 39 | 35 | 30 | 26 | 21 | 17 | 13 | 9 | 4 | | | | 34 | | | | | | | | | | | | | | 35 | 45 | 41 | 37 | 32 | 28 | 24 | 19 | 15 | 12 | 7 | 3 | | | 35 36 | 47 | 43 | 38 | 34 | 30 | 26 | 22 | 18 | 14 | 10 | 6 | 2 | | 36 37 | 48 | 44 | 40 | 36 | 32 | 28 | 24 | 20 | 16 | 12 | 8 | 5 | 1 | 37 38 | 50 | 46 | 42 | 38 | 34 | 30 | 26 | 22 | 18 | 15 | 11 | 7 | 3 | 38 39 | 52 | 48 | 44 | 40 | 36 | 32 | 28 | 24 | 20 | 17 | 13 | 9 | 6 | 39 | | | | | | | | | | | | | | 40 | 53 | 49 | 45 | 41 | 38 | 34 | 30 | 26 | 22 | 19 | 16 | 12 | 8 | 40 41 | 54 | 50 | 46 | 43 | 39 | 36 | 32 | 29 | 24 | 21 | 18 | 14 | 10 | 41 42 | 55 | 51 | 48 | 44 | 40 | 37 | 34 | 30 | 27 | 23 | 20 | 16 | 13 | 42 43 | 56 | 52 | 49 | 46 | 42 | 38 | 35 | 32 | 29 | 25 | 22 | 19 | 15 | 43 44 | 57 | 53 | 50 | 47 | 43 | 40 | 37 | 33 | 30 | 27 | 24 | 21 | 17 | 44 | | | | | | | | | | | | | | 45 | 58 | 54 | 51 | 48 | 44 | 41 | 38 | 35 | 32 | 29 | 25 | 22 | 19 | 45 46 | 58 | 55 | 52 | 49 | 46 | 42 | 39 | 36 | 33 | 30 | 27 | 23 | 21 | 46 47 | 59 | 56 | 53 | 50 | 47 | 44 | 40 | 38 | 34 | 31 | 28 | 25 | 22 | 47 48 | 60 | 56 | 53 | 51 | 48 | 45 | 42 | 39 | 36 | 33 | 30 | 27 | 24 | 48 49 | 60 | 57 | 54 | 52 | 49 | 46 | 43 | 40 | 37 | 34 | 31 | 29 | 26 | 49 | | | | | | | | | | | | | | 50 | 61 | 58 | 55 | 52 | 50 | 47 | 44 | 41 | 38 | 36 | 33 | 30 | 27 | 50 51 | 62 | 59 | 56 | 53 | 50 | 48 | 45 | 42 | 39 | 37 | 34 | 31 | 28 | 51 52 | 63 | 60 | 57 | 54 | 51 | 48 | 46 | 43 | 40 | 38 | 35 | 33 | 30 | 52 53 | 63 | 61 | 58 | 55 | 52 | 49 | 47 | 44 | 42 | 39 | 36 | 34 | 31 | 53 54 | 64 | 61 | 59 | 56 | 53 | 50 | 48 | 45 | 43 | 40 | 38 | 35 | 32 | 54 | | | | | | | | | | | | | | 55 | 65 | 62 | 59 | 57 | 54 | 51 | 49 | 46 | 43 | 41 | 39 | 36 | 34 | 55 56 | 65 | 63 | 60 | 57 | 55 | 52 | 50 | 47 | 44 | 42 | 40 | 37 | 35 | 56 57 | 66 | 64 | 61 | 58 | 55 | 53 | 50 | 48 | 45 | 43 | 40 | 38 | 36 | 57 58 | 67 | 64 | 61 | 59 | 56 | 53 | 51 | 49 | 46 | 44 | 42 | 39 | 37 | 58 59 | 67 | 65 | 62 | 60 | 57 | 54 | 52 | 49 | 47 | 45 | 43 | 40 | 38 | 59 | | | | | | | | | | | | | | 60 | 68 | 65 | 63 | 60 | 58 | 55 | 53 | 50 | 48 | 46 | 44 | 41 | 39 | 60 61 | 68 | 66 | 63 | 61 | 58 | 56 | 54 | 51 | 49 | 47 | 44 | 42 | 40 | 61 62 | 69 | 66 | 64 | 61 | 59 | 57 | 54 | 52 | 50 | 47 | 45 | 43 | 41 | 62 63 | 69 | 67 | 64 | 62 | 60 | 57 | 55 | 53 | 51 | 48 | 46 | 44 | 42 | 63 64 | 70 | 67 | 65 | 62 | 60 | 58 | 56 | 53 | 51 | 49 | 47 | 45 | 43 | 64 | | | | | | | | | | | | | | 65 | 70 | 68 | 65 | 63 | 61 | 59 | 56 | 54 | 52 | 50 | 48 | 46 | 44 | 65 66 | 71 | 68 | 66 | 63 | 61 | 59 | 57 | 55 | 53 | 51 | 49 | 47 | 45 | 66 67 | 71 | 69 | 66 | 64 | 62 | 60 | 58 | 55 | 53 | 51 | 49 | 47 | 45 | 67 68 | 71 | 69 | 67 | 65 | 63 | 60 | 58 | 56 | 54 | 52 | 50 | 48 | 46 | 68 69 | 72 | 70 | 67 | 65 | 63 | 61 | 59 | 57 | 55 | 53 | 51 | 49 | 47 | 69 | | | | | | | | | | | | | | 70 | 72 | 70 | 68 | 66 | 64 | 62 | 60 | 57 | 55 | 53 | 52 | 50 | 48 | 70 71 | 72 | 70 | 68 | 66 | 64 | 62 | 60 | 58 | 56 | 54 | 52 | 50 | 48 | 71 72 | 73 | 71 | 69 | 67 | 65 | 63 | 61 | 59 | 57 | 55 | 53 | 51 | 49 | 72 73 | 73 | 71 | 69 | 67 | 65 | 63 | 61 | 59 | 57 | 55 | 53 | 52 | 50 | 73 74 | 74 | 72 | 70 | 68 | 66 | 64 | 62 | 60 | 58 | 56 | 54 | 52 | 50 | 74 | | | | | | | | | | | | | | 75 | 74 | 72 | 70 | 68 | 66 | 64 | 62 | 60 | 58 | 56 | 55 | 53 | 51 | 75 76 | 74 | 72 | 70 | 68 | 66 | 64 | 63 | 61 | 59 | 57 | 55 | 53 | 52 | 76 77 | 74 | 73 | 71 | 69 | 67 | 65 | 63 | 61 | 59 | 57 | 56 | 54 | 52 | 77 78 | 75 | 73 | 71 | 69 | 67 | 65 | 63 | 62 | 60 | 58 | 56 | 54 | 53 | 78 79 | 75 | 73 | 71 | 70 | 68 | 66 | 64 | 62 | 60 | 58 | 57 | 55 | 53 | 79 | | | | | | | | | | | | | | 80 | 75 | 73 | 72 | 70 | 68 | 66 | 64 | 63 | 61 | 59 | 57 | 55 | 54 | 80 ------+----+----+----+----+----+----+----+----+-----+-----+-----+-----+-----+------ _t._ |6°.0|6°.5|7°.0|7°.5|8°.0|8°.5|9°.0|9°.5|10°.0|10°.5|11°.0|11°.5|12°0|_t._ ======+====+====+====+====+====+====+====+====+=====+=====+=====+=====+=====+======

TABLE II.——RELATIVE HUMIDITY, PER CENT.

TABLE III.——REDUCTION OF BAROMETER READING TO 32°.

===+========================================================================================= | Inches. +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- °F | 24.0| 24.5| 25.0| 25.5| 26.0| 26.5| 27.0| 27.5| 28.0| 28.5| 29.0| 29.5| 30.0| 30.5| 31.0 ---+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- 30|-.003|-.003|-.003|-.003|-.003|-.003|-.003|-.003|-.003|-.004|-.004|-.004|-.004|-.004|-.004 31| .005| .005| .005| .005| .006| .006| .006| .006| .006| .006| .006| .006| .006| .007| .007 32| .007| .008| .008| .008| .008| .008| .008| .008| .009| .009| .009| .009| .009| .009| .009 33| .010| .010| .010| .010| .010| .010| .011| .011| .011| .011| .012| .012| .012| .012| .012 34| .012| .012| .012| .012| .013| .013| .013| .013| .014| .014| .014| .014| .015| .015| .015 | | | | | | | | | | | | | | | 35| .014| .014| .014| .015| .015| .015| .016| .016| .016| .016| .017| .017| .017| .018| .018 36| .016| .016| .017| .017| .017| .018| .018| .018| .019| .019| .019| .020| .020| .020| .021 37| .018| .019| .019| .019| .020| .020| .021| .021| .021| .022| .022| .022| .023| .023| .024 38| .020| .021| .021| .022| .022| .022| .023| .023| .024| .024| .025| .025| .026| .026| .026 39| .023| .023| .024| .024| .024| .025| .025| .026| .026| .027| .027| .028| .028| .029| .029 | | | | | | | | | | | | | | | 40| .025| .025| .026| .026| .027| .027| .028| .028| .029| .030| .030| .030| .031| .031| .032 41| .027| .027| .028| .029| .029| .030| .030| .031| .031| .032| .033| .033| .034| .034| .035 42| .029| .030| .030| .031| .032| .032| .033| .033| .034| .034| .035| .036| .036| .037| .038 43| .031| .032| .033| .033| .034| .035| .035| .036| .036| .037| .038| .038| .039| .040| .040 44| .033| .034| .035| .035| .036| .037| .038| .038| .039| .040| .040| .041| .042| .042| .043 | | | | | | | | | | | | | | | 45| .036| .037| .037| .038| .039| .039| .040| .041| .042| .042| .043| .044| .045| .045| .046 46| .038| .038| .039| .040| .041| .042| .043| .043| .044| .045| .046| .046| .047| .048| .049 47| .040| .041| .042| .042| .043| .044| .045| .046| .047| .048| .048| .049| .050| .051| .052 48| .042| .043| .044| .045| .046| .047| .047| .048| .049| .050| .051| .052| .053| .053| .054 49| .044| .045| .046| .047| .048| .049| .050| .051| .052| .052| .054| .054| .055| .056| .057 | | | | | | | | | | | | | | | 50| .046| .047| .048| .049| .050| .051| .052| .053| .054| .055| .056| .057| .058| .059| .060 51| .049| .050| .051| .052| .053| .054| .055| .056| .057| .058| .059| .060| .061| .062| .063 52| .051| .052| .053| .054| .055| .056| .057| .058| .059| .060| .061| .062| .064| .065| .066 53| .053| .054| .055| .056| .057| .058| .060| .061| .062| .063| .064| .065| .066| .067| .068 54| .055| .056| .057| .058| .060| .061| .062| .063| .064| .065| .067| .068| .069| .070| .071 | | | | | | | | | | | | | | | 55| .057| .058| .060| .061| .062| .063| .064| .065| .066| .068| .069| .070| .071| .073| .074 56| .060| .061| .062| .063| .064| .065| .067| .068| .069| .070| .072| .073| .074| .075| .077 57| .062| .063| .064| .065| .067| .068| .069| .070| .072| .073| .075| .076| .077| .078| .080 58| .064| .065| .066| .068| .069| .070| .071| .073| .074| .076| .077| .078| .080| .081| .082 59| .066| .068| .069| .070| .072| .073| .074| .075| .077| .078| .080| .081| .083| .084| .085 | | | | | | | | | | | | | | | 60| .068| .070| .071| .072| .074| .076| .077| .078| .079| .081| .082| .084| .085| .086| .088 61| .070| .072| .073| .074| .076| .077| .079| .080| .082| .083| .085| .086| .088| .089| .091 62| .073| .074| .076| .077| .079| .080| .082| .083| .085| .086| .088| .089| .091| .092| .094 63| .075| .076| .078| .079| .081| .082| .084| .085| .087| .088| .090| .091| .093| .095| .096 64| .077| .078| .080| .081| .083| .085| .086| .088| .090| .091| .093| .094| .096| .097| .099 | | | | | | | | | | | | | | | 65|-.079|-.080|-.082|-.084|-.086|-.087|-.089|-.090|-.092|-.093|-.095|-.097|-.099|-.100|-.102 ===+=========================================================================================

TABLE III.——REDUCTION OF BAROMETER READING TO 32°.——_Continued._

===+========================================================================================= | Inches. +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- °F | 24.0| 24.5| 25.0| 25.5| 26.0| 26.5| 27.0| 27.5| 28.0| 28.5| 29.0| 29.5| 30.0| 30.5| 31.0 ---+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- 65|-.079|-.080|-.082|-.084|-.086|-.087|-.089|-.090|-.092|-.093|-.095|-.097|-.099|-.100|-.102 66| .081| .083| .085| .086| .088| .089| .091| .093| .095| .096| .098| .099| .101| .103| .105 67| .083| .085| .087| .088| .090| .092| .094| .095| .097| .099| .101| .102| .104| .106| .108 68| .085| .087| .089| .090| .093| .094| .096| .098| .100| .101| .103| .105| .107| .108| .110 69| .088| .089| .091| .093| .095| .097| .099| .100| .102| .104| .106| .107| .110| .111| .113 | | | | | | | | | | | | | | | 70| .090| .092| .094| .096| .097| .099| .101| .103| .105| .106| .109| .110| .112| .114| .116 71| .092| .094| .096| .098| .100| .101| .103| .105| .107| .109| .111| .113| .115| .116| .119 72| .094| .096| .098| .100| .102| .104| .106| .108| .110| .112| .114| .116| .118| .120| .122 73| .096| .098| .100| .102| .104| .106| .108| .110| .112| .114| .116| .118| .120| .122| .124 74| .098| .100| .103| .105| .107| .109| .111| .113| .115| .117| .119| .121| .123| .125| .127 | | | | | | | | | | | | | | | 75| .101| .102| .105| .106| .109| .111| .113| .115| .117| .119| .122| .124| .126| .128| .130 76| .103| .104| .107| .109| .111| .113| .116| .118| .120| .122| .124| .126| .128| .130| .133 77| .105| .107| .109| .111| .114| .116| .118| .120| .122| .124| .127| .129| .131| .133| .136 78| .107| .109| .112| .113| .116| .118| .120| .122| .125| .127| .129| .131| .134| .136| .138 79| .109| .111| .114| .116| .118| .120| .123| .125| .127| .129| .132| .134| .137| .139| .141 | | | | | | | | | | | | | | | 80| .111| .113| .116| .118| .121| .123| .125| .127| .130| .132| .135| .137| .139| .141| .144 81| .114| .116| .118| .120| .123| .125| .128| .130| .132| .134| .137| .139| .142| .144| .147 82| .116| .118| .121| .122| .125| .128| .130| .132| .135| .137| .140| .142| .145| .147| .149 83| .118| .120| .123| .125| .128| .130| .133| .135| .138| .140| .142| .145| .147| .149| .152 84| .120| .122| .125| .127| .130| .132| .135| .138| .140| .142| .145| .147| .150| .152| .155 | | | | | | | | | | | | | | | 85| .122| .124| .127| .129| .132| .134| .137| .139| .143| .145| .148| .150| .153| .155| .158 86| .124| .126| .128| .130| .135| .137| .140| .143| .145| .148| .150| .153| .155| .158| .161 87| .126| .129| .132| .134| .137| .139| .142| .144| .148| .150| .153| .155| .158| .161| .163 88| .129| .131| .134| .137| .139| .142| .145| .147| .150| .152| .155| .158| .161| .163| .166 89| .131| .133| .136| .139| .142| .144| .147| .150| .153| .155| .158| .161| .164| .166| .169 | | | | | | | | | | | | | | | 90| .133| .136| .138| .141| .144| .147| .150| .153| .155| .157| .161| .164| .166| .169| .172 91| .135| .138| .141| .143| .146| .149| .152| .155| .158| .160| .163| .166| .169| .172| .175 92| .137| .140| .143| .146| .149| .152| .154| .157| .160| .163| .166| .169| .172| .175| .177 93| .139| .142| .145| .148| .151| .154| .157| .160| .163| .166| .168| .171| .174| .177| .180 94| .142| .145| .147| .150| .153| .156| .159| .162| .165| .168| .171| .174| .177| .180| .183 | | | | | | | | | | | | | | | 95| .144| .147| .150| .153| .156| .159| .162| .165| .168| .171| .174| .177| .180| .183| .186 96| .146| .149| .152| .155| .158| .161| .164| .167| .170| .173| .176| .179| .182| .185| .188 97| .148| .151| .154| .157| .160| .164| .167| .170| .173| .176| .179| .182| .185| .188| .191 98| .150| .153| .156| .160| .163| .166| .169| .172| .175| .178| .181| .185| .188| .191| .194 99| .152| .155| .159| .162| .165| .168| .171| .175| .178| .181| .184| .187| .190| .194| .197 | | | | | | | | | | | | | | | 100|-.154|-.157|-.161|-.164|-.167|-.171|-.174|-.177|-.180|-.184|-.187|-.190|-.193|-.197|-.200 ---+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----

TABLE IV.——TABLE FOR REDUCING OBSERVATIONS OF THE BAROMETER TO SEA LEVEL, CORRECTION ADDITIVE.

==========+======================================================================= Height, in| Temperature of external air——degrees Fahrenheit. feet. | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- | -20°| -10°| 0° | 10°| 20°| 30°| 40°| 50°| 60°| 70°| 80°| 90°| 100° ----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- 10| .013| .013| .012| .012| .012| .012| .011| .011| .011| .011| .010| .010| .010 20| .026| .025| .025| .024| .023| .023| .023| .022| .022| .021| .021| .020| .020 30| .039| .038| .037| .036| .035| .034| .034| .033| .032| .032| .031| .030| .030 40| .052| .050| .049| .048| .047| .046| .045| .044| .043| .042| .041| .040| .040 | | | | | | | | | | | | | 50| .065| .063| .061| .060| .059| .058| .056| .055| .054| .053| .052| .051| .050 60| .077| .076| .074| .072| .070| .069| .068| .066| .065| .063| .062| .061| .059 70| .090| .088| .086| .084| .082| .081| .078| .077| .076| .074| .072| .071| .069 80| .103| .101| .098| .096| .094| .092| .090| .088| .086| .084| .082| .081| .079 90| .116| .113| .111| .108| .105| .104| .101| .099| .097| .095| .093| .091| .089 | | | | | | | | | | | | | 100| .129| .126| .123| .120| .117| .115| .112| .110| .108| .105| .103| .101| .099 110| .142| .139| .135| .132| .129| .126| .123| .121| .119| .116| .113| .111| .109 120| .155| .151| .148| .144| .140| .138| .134| .132| .129| .126| .124| .121| .119 130| .168| .164| .160| .156| .152| .149| .146| .143| .140| .137| .134| .131| .129 140| .181| .176| .172| .168| .164| .161| .157| .154| .151| .147| .144| .141| .139 | | | | | | | | | | | | | 150| .194| .189| .185| .180| .176| .172| .168| .165| .162| .158| .155| .152| .149 160| .206| .201| .197| .192| .187| .183| .179| .176| .172| .168| .165| .162| .158 170| .219| .214| .209| .204| .199| .195| .190| .187| .183| .179| .175| .172| .168 180| .232| .227| .222| .216| .211| .206| .202| .198| .194| .189| .185| .182| .178 190| .245| .239| .234| .228| .222| .218| .213| .209| .204| .200| .196| .192| .188 | | | | | | | | | | | | | 200| .258| .252| .246| .240| .234| .229| .224| .220| .215| .210| .206| .202| .198 210| .271| .264| .258| .252| .246| .240| .235| .231| .226| .221| .216| .212| .208 220| .284| .277| .270| .264| .257| .252| .246| .242| .236| .231| .227| .222| .218 230| .296| .289| .283| .276| .269| .263| .257| .253| .247| .242| .237| .232| .228 240| .309| .302| .295| .288| .281| .275| .269| .264| .258| .252| .248| .242| .238 | | | | | | | | | | | | | 250| .322| .314| .307| .300| .293| .286| .280| .275| .269| .263| .258| .253| .248 260| .335| .327| .319| .311| .304| .297| .291| .285| .279| .273| .268| .263| .257 270| .348| .339| .331| .323| .316| .309| .302| .296| .290| .284| .278| .273| .267 280| .360| .352| .344| .335| .328| .320| .314| .307| .301| .294| .288| .283| .277 290| .373| .364| .356| .347| .339| .332| .325| .318| .311| .305| .299| .293| .287 | | | | | | | | | | | | | 300| .386| .377| .368| .359| .351| .343| .336| .329| .322| .315| .309| .303| .297 310| .399| .389| .380| .371| .363| .354| .347| .340| .333| .326| .319| .313| .307 320| .412| .402| .392| .383| .374| .366| .358| .351| .343| .336| .329| .323| .317 330| .424| .414| .404| .395| .386| .377| .369| .362| .354| .347| .340| .333| .326 340| .437| .427| .416| .407| .397| .389| .380| .373| .365| .357| .350| .343| .336 | | | | | | | | | | | | | 350| .450| .439| .429| .419| .409| .400| .392| .384| .376| .368| .360| .353| .346 360| .463| .451| .441| .430| .421| .411| .403| .394| .386| .378| .370| .363| .356 370| .476| .464| .453| .442| .432| .423| .414| .405| .397| .389| .380| .373| .366 380| .488| .476| .465| .454| .444| .434| .425| .416| .408| .399| .391| .383| .375 390| .501| .489| .477| .466| .455| .446| .436| .427| .418| .410| .401| .393| .385 | | | | | | | | | | | | | 400| .514| .501| .489| .478| .467| .457| .447| .438| .429| .420| .411| .403| .395 410| .527| .513| .501| .490| .479| .468| .458| .449| .440| .430| .421| .413| .405 420| .539| .526| .513| .502| .490| .480| .469| .460| .450| .441| .431| .423| .415 430| .552| .538| .525| .513| .502| .491| .480| .470| .461| .451| .442| .433| .425 440| .565| .551| .537| .525| .513| .502| .491| .481| .471| .462| .452| .443| .434 | | | | | | | | | | | | | 450| .578| .563| .550| .537| .525| .513| .503| .492| .482| .472| .462| .453| .444 460| .590| .575| .562| .549| .537| .525| .514| .503| .493| .482| .472| .463| .454 470| .603| .588| .574| .561| .548| .536| .525| .514| .503| .493| .482| .473| .464 480| .616| .600| .586| .572| .560| .547| .536| .524| .514| .503| .493| .483| .474 490| .628| .613| .598| .584| .571| .559| .547| .535| .524| .514| .503| .493| .483 | | | | | | | | | | | | | 500| .641| .625| .610| .596| .583| .570| .558| .546| .535| .524| .513| .503| .493 510| .654| .637| .622| .608| .594| .581| .569| .557| .545| .534| .523| .513| .503 520| .666| .650| .634| .620| .606| .593| .580| .568| .556| .545| .533| .523| .513 530| .679| .662| .646| .631| .617| .604| .591| .578| .566| .555| .544| .533| .522 540| .691| .675| .658| .643| .629| .615| .602| .589| .577| .565| .554| .543| .532 ====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====

TABLE IV.——FOR REDUCING OBSERVATIONS OF THE BAROMETER TO SEA LEVEL.——_Continued._

==========+======================================================================= Height, in| Temperature of external air——degrees Fahrenheit. feet. | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- | -20°| -10°| 0° | 10°| 20°| 30°| 40°| 50°| 60°| 70°| 80°| 90°| 100° ----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- 550| .704| .687| .670| .655| .640| .626| .613| .600| .587| .575| .564| .553| .542 560| .717| .699| .683| .667| .652| .638| .624| .611| .598| .586| .574| .563| .552 570| .729| .712| .695| .679| .663| .649| .635| .622| .608| .596| .584| .573| .562 580| .742| .724| .707| .690| .675| .660| .646| .632| .619| .606| .595| .583| .571 590| .754| .737| .719| .702| .686| .672| .657| .643| .629| .617| .605| .593| .581 | | | | | | | | | | | | | 600| .767| .749| .731| .714| .698| .683| .668| .654| .640| .627| .615| .603| .591 610| .780| .761| .743| .726| .709| .694| .679| .665| .650| .637| .625| .613| .601 620| .792| .774| .755| .738| .721| .705| .690| .675| .661| .648| .635| .623| .611 630| .805| .786| .767| .749| .732| .717| .701| .686| .671| .658| .645| .633| .620 640| .817| .798| .779| .761| .744| .728| .712| .697| .682| .668| .655| .643| .630 | | | | | | | | | | | | | 650| .830| .811| .791| .773| .755| .739| .723| .708| .692| .679| .666| .653| .640 660| .843| .823| .803| .785| .767| .750| .734| .718| .703| .689| .676| .662| .650 670| .855| .835| .815| .797| .778| .761| .745| .729| .713| .699| .686| .672| .660 680| .868| .847| .827| .808| .790| .773| .756| .740| .724| .709| .696| .682| .669 690| .880| .860| .839| .820| .801| .784| .767| .750| .734| .720| .706| .692| .679 | | | | | | | | | | | | | 700| .893| .872| .851| .832| .813| .795| .778| .761| .745| .730| .716| .702| .689 710| .905| .884| .863| .844| .824| .806| .789| .772| .755| .740| .726| .712| .698 720| .918| .896| .875| .855| .836| .817| .800| .782| .766| .751| .736| .722| .708 730| .930| .909| .887| .867| .847| .829| .811| .793| .776| .761| .746| .732| .718 740| .943| .921| .899| .879| .859| .840| .822| .804| .787| .771| .756| .742| .728 | | | | | | | | | | | | | 750| .955| .933| .911| .891| .870| .851| .833| .815| .797| .782| .767| .752| .738 760| .968| .945| .922| .902| .881| .862| .843| .825| .808| .792| .777| .761| .747 770| .980| .957| .934| .914| .893| .873| .854| .836| .818| .802| .787| .771| .757 780| .993| .970| .946| .926| .904| .885| .865| .847| .829| .812| .797| .781| .767 790|1.005| .982| .958| .937| .916| .896| .876| .857| .839| .823| .807| .791| .776 | | | | | | | | | | | | | 800|1.018| .994| .970| .949| .927| .907| .887| .868| .850| .833| .817| .801| .786 810|1.030|1.006| .982| .961| .938| .918| .898| .878| .860| .843| .827| .811| .796 820|1.043|1.018| .994| .972| .950| .929| .909| .889| .871| .854| .937| .821| .805 830|1.055|1.031|1.006| .984| .961| .940| .920| .900| .881| .864| .847| .831| .815 840|1.068|1.043|1.018| .995| .973| .951| .931| .911| .892| .874| .857| .841| .825 | | | | | | | | | | | | | 850|1.080|1.055|1.030|1.007| .984| .962| .942| .922| .902| .885| .867| .851| .835 860|1.093|1.067|1.041|1.019| .995| .974| .952| .932| .913| .895| .877| .860| .844 870|1.105|1.079|1.053|1.030|1.007| .985| .963| .943| .923| .905| .887| .870| .854 880|1.118|1.092|1.065|1.042|1.018| .996| .974| .954| .934| .915| .897| .880| .864 890|1.130|1.104|1.077|1.053|1.030|1.007| .985| .904| .944| .926| .907| .890| .873 | | | | | | | | | | | | | 900|1.143|1.116|1.089|1.065|1.041|1.018| .996| .975| .955| .936| .917| .900| .883 910|1.155|1.128|1.101|1.077|1.052|1.029|1.007| .986| .965| .946| .927| .910| .893 920|1.168|1.140|1.113|1.088|1.064|1.040|1.018| .996| .976| .956| .937| .920| .902 930|1.180|1.152|1.125|1.100|1.075|1.051|1.029|1.007| .986| .967| .947| .929| .912 940|1.193|1.164|1.137|1.111|1.086|1.062|1.040|1.017| .997| .977| .957| .939| .921 | | | | | | | | | | | | | 950|1.205|1.177|1.149|1.123|1.098|1.074|1.051|1.028|1.007| .987| .967| .949| .931 960|1.217|1.189|1.160|1.135|1.109|1.085|1.061|1.039|1.017| .997| .977| .959| .941 970|1.230|1.201|1.172|1.146|1.120|1.096|1.072|1.049|1.028|1.007| .987| .969| .950 980|1.242|1.213|1.184|1.158|1.131|1.107|1.083|1.060|1.038|1.018| .997| .978| .960 990|1.255|1.225|1.196|1.169|1.143|1.118|1.094|1.070|1.049|1.028|1.007| .988| .969 | | | | | | | | | | | | | 1000|1.267|1.237|1.208|1.181|1.154|1.129|1.105|1.081|1.059|1.038|1.017| .998| .979 1010|1.279|1.249|1.220|1.192|1.165|1.140|1.116|1.092|1.069|1.048|1.027|1.008| .989 1020|1.292|1.261|1.232|1.204|1.177|1.151|1.127|1.102|1.080|1.058|1.037|1.018| .998 1030|1.304|1.273|1.243|1.215|1.188|1.162|1.137|1.113|1.090|1.069|1.047|1.027|1.008 1040|1.317|1.285|1.255|1.227|1.199|1.173|1.148|1.123|1.101|1.079|1.057|1.037|1.017 | | | | | | | | | | | | | 1050|1.329|1.298|1.267|1.238|1.211|1.184|1.159|1.134|1.111|1.089|1.067|1.047|1.027 1060|1.341|1.310|1.279|1.250|1.222|1.195|1.170|1.145|1.121|1.099|1.077|1.057|1.037 1070|1.354|1.322|1.291|1.261|1.233|1.206|1.181|1.155|1.132|1.109|1.087|1.067|1.046 1080|1.366|1.334|1.302|1.273|1.244|1.217|1.191|1.166|1.142|1.120|1.097|1.076|1.056 1090|1.379|1.346|1.314|1.284|1.256|1.228|1.202|1.176|1.153|1.130|1.107|1.086|1.065 ====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====

TABLE IV.——FOR REDUCING OBSERVATIONS OF THE BAROMETER TO SEA LEVEL.——_Continued._

==========+======================================================================= Height, in| Temperature of external air——degrees Fahrenheit. feet. | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- | -20°| -10°| 0° | 10°| 20°| 30°| 40°| 50°| 60°| 70°| 80°| 90°| 100° ----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- 1100|1.391|1.358|1.326|1.296|1.267|1.239|1.213|1.187|1.163|1.140|1.117|1.096|1.075 1110|1.403|1.370|1.338|1.307|1.278|1.250|1.224|1.198|1.173|1.150|1.127|1.106|1.085 1120|1.416|1.382|1.350|1.319|1.289|1.261|1.235|1.208|1.184|1.160|1.137|1.115|1.094 1130|1.428|1.394|1.361|1.330|1.301|1.272|1.245|1.219|1.194|1.170|1.147|1.125|1.104 1140|1.440|1.406|1.373|1.342|1.312|1.283|1.256|1.229|1.204|1.180|1.157|1.135|1.113 | | | | | | | | | | | | | 1150|1.453|1.418|1.385|1.353|1.323|1.294|1.267|1.240|1.215|1.191|1.167|1.145|1.123 1160|1.465|1.430|1.397|1.365|1.334|1.305|1.278|1.251|1.225|1.201|1.177|1.154|1.133 1170|1.477|1.442|1.409|1.376|1.345|1.315|1.289|1.261|1.235|1.211|1.187|1.164|1.142 1180|1.489|1.454|1.420|1.388|1.357|1.327|1.299|1.272|1.245|1.221|1.197|1.174|1.152 1190|1.502|1.466|1.432|1.399|1.368|1.338|1.310|1.282|1.256|1.231|1.207|1.183|1.161 | | | | | | | | | | | | | 1200|1.514|1.478|1.444|1.411|1.379|1.349|1.321|1.293|1.266|1.241|1.217|1.193|1.171 1210|1.526|1.490|1.456|1.422|1.390|1.360|1.332|1.303|1.276|1.251|1.227|1.203|1.180 1220|1.539|1.502|1.467|1.434|1.401|1.371|1.342|1.314|1.288|1.261|1.237|1.212|1.190 1230|1.551|1.514|1.479|1.445|1.413|1.382|1.353|1.324|1.297|1.271|1.247|1.222|1.199 1240|1.563|1.526|1.491|1.457|1.424|1.393|1.364|1.335|1.307|1.281|1.257|1.232|1.209 | | | | | | | | | | | | | 1250|1.576|1.538|1.502|1.468|1.435|1.404|1.374|1.345|1.317|1.291|1.266|1.242|1.218 1260|1.588|1.550|1.514|1.479|1.446|1.415|1.385|1.356|1.328|1.302|1.276|1.251|1.228 1270|1.600|1.562|1.526|1.491|1.457|1.426|1.396|1.366|1.338|1.312|1.286|1.261|1.237 1280|1.612|1.574|1.538|1.502|1.469|1.437|1.407|1.377|1.348|1.322|1.296|1.271|1.247 1290|1.625|1.586|1.549|1.514|1.480|1.448|1.417|1.387|1.359|1.332|1.306|1.280|1.256 | | | | | | | | | | | | | 1300|1.637|1.598|1.561|1.525|1.491|1.459|1.428|1.398|1.369|1.342|1.316|1.290|1.266 1310|1.649|1.610|1.573|1.536|1.502|1.470|1.439|1.408|1.379|1.352|1.326|1.300|1.275 1320|1.661|1.622|1.584|1.548|1.513|1.481|1.449|1.419|1.390|1.362|1.336|1.309|1.285 1330|1.674|1.634|1.596|1.559|1.525|1.492|1.460|1.429|1.400|1.372|1.346|1.319|1.294 1340|1.686|1.640|1.608|1.571|1.536|1.503|1.471|1.440|1.410|1.382|1.356|1.329|1.304 | | | | | | | | | | | | | 1350|1.698|1.658|1.620|1.582|1.547|1.514|1.482|1.450|1.420|1.393|1.366|1.339|1.313 1360|1.710|1.669|1.631|1.593|1.558|1.524|1.492|1.461|1.431|1.403|1.375|1.348|1.323 1870|1.722|1.681|1.643|1.605|1.569|1.535|1.503|1.471|1.441|1.413|1.385|1.358|1.332 1380|1.735|1.693|1.655|1.616|1.581|1.546|1.514|1.482|1.451|1.423|1.395|1.368|1.342 1390|1.747|1.705|1.666|1.628|1.592|1.557|1.524|1.492|1.462|1.433|1.405|1.377|1.351 | | | | | | | | | | | | | 1400|1.759|1.717|1.678|1.639|1.603|1.568|1.535|1.503|1.472|1.443|1.415|1.387|1.361 1410|1.771|1.729|1.690|1.650|1.614|1.579|1.546|1.513|1.482|1.453|1.425|1.397|1.370 1420|1.783|1.741|1.701|1.662|1.625|1.590|1.556|1.524|1.492|1.463|1.435|1.406|1.380 1430|1.796|1.753|1.713|1.673|1.636|1.601|1.567|1.534|1.503|1.473|1.444|1.416|1.389 1440|1.808|1.765|1.724|1.685|1.047|1.612|1.577|1.545|1.513|1.483|1.454|1.426|1.399 | | | | | | | | | | | | | 1450|1.820|1.777|1.736|1.696|1.658|1.623|1.588|1.555|1.523|1.493|1.464|1.436|1.408 1460|1.832|1.788|1.748|1.707|1.670|1.633|1.599|1.565|1.533|1.503|1.474|1.445|1.418 1470|1.844|1.800|1.759|1.719|1.081|1.644|1.609|1.576|1.543|1.513|1.484|1.455|1.427 1480|1.857|1.812|1.771|1.730|1.692|1.655|1.620|1.586|1.554|1.523|1.493|1.465|1.437 1490|1.869|1.824|1.782|1.742|1.703|1.666|1.630|1.597|1.564|1.533|1.503|1.474|1.446 | | | | | | | | | | | | | 1500|1.881|1.836|1.794|1.753|1.714|1.677|1.641|1.607|1.574|1.543|1.513|1.484|1.456 ====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====

APPENDIX A.

SUGGESTIONS TO TEACHERS.

It is the object of this book to lead the student to the independent discovery of the most important facts in our ordinary weather conditions, and of the interrelations of the different weather elements. This practical study having taught something as to the real nature of atmospheric phenomena by actual observation, rapid and substantial progress may be made in the knowledge of the distribution and of the explanation of similar phenomena in other parts of the world, as derived through a study of the text-books. By means of this combination of the two kinds of study, the inductive and the didactic, the advantages of both may be preserved, and the slow progress of the first method and the unsound progress of the second may be avoided. This book is not a text-book, and it therefore does not attempt to give explanations of various phenomena discovered by the class. Explanations will, of course, be called for by the scholars, in increasing number as the work progresses, and the larger relations of the study become apparent. It is best, if possible, to leave the more complicated matters (such as the cause of the deflection of the wind from the gradient, of cyclones and anticyclones, etc.) until the subjects can be taken up in detail and fully explained, for instance in the later years of the high school course. It is not advisable to raise such complicated questions in the grammar school work if they can be avoided. The teacher who has a fairly good knowledge of one comprehensive modern text-book of meteorology, such as Davis’s _Elementary Meteorology_, will find himself sufficiently well equipped to answer the questions put by the class.

The value of the work outlined in this little book can be much increased if the larger applications of the lessons here learned are strongly emphasized. Suggestions along this line have been made in fine print throughout the text, but the examples given may be further extended to the great advantage of the student. Careful attention ought to be given to the formulating and writing out of the generalizations reached by the class, for in these written summaries the results are preserved in compact form.