A Treatise on Meteorological Instruments Explanatory of Their Scientific Principles, Method of Construction, and Practical Utility

=1. Principle of the Barometer.=--The first instrument which gave the exact measure of the pressure of the atmosphere was invented by Torricelli, in 1643. It is constructed as f...

=145. Chemical Weather Glass.=--This curious instrument appears to have been invented more than a hundred years ago, but the original maker is not known. It is simply a glass vi...

Bodies are said to possess the same temperature, when the amounts of heat which they respectively contain act outwardly with the same intensity of transfer or absorption, produc...

=69. Importance of Self-Registering Thermometers.=--Heat being apparently the most effective agent in producing meteorological phenomena, the determination of the highest temper...

=43. Desirability of Magnifying the Barometer Range.=--The limits within which the ordinary barometric column oscillates, do not exceed four inches for extreme range, while the...

=122. The Vane.=--The instrument by which the wind's direction is most generally noted, is the vane, or weather-cock, and all that need be said of it here is that the points nor...

=37. The Syphon Tube Mountain Barometer, on Gay Lussac's principle=, constructed as described at page 31, and fixed in a metallic tubular frame, forms a simple and light travell...

=97. Hygrometric Substances.=--The instruments devised for the purpose of ascertaining the humidity of the atmosphere are termed _hygrometers_. The earliest invented hygrometers...

=131. Atmospheric Electroscope.=--The simplest instrument for ascertaining at any time the electric condition of the atmosphere is an electroscope composed of two equal pieces o...

=110. Howard's Rain-Gauge.=--It consists of a copper funnel, a stout glass or stone bottle, and a measuring glass. The bottle is to be placed upon the ground, with the funnel re...

=91. Ebullition.=--The temperature at which a fluid _boils_ is called the _boiling-point_ of that particular fluid. It is different for different liquids; and, moreover, in the...

=82. Solar and Terrestrial Radiation considered.=--The surface of the earth absorbs the heat of the sun during the day, and radiates heat into space during the night. The envelo...

=33. Milne's Self-Registering Barometer.=--For a long time a good and accurate self-recording barometer was much desired. This want is now satisfactorily supplied, not by one, b...

=89. On Sixe's Principle.=--Thermometers for ascertaining the temperature of the sea at various depths are constructed to register either the maximum or minimum temperature, or...

=30. Principle of.=--If some mercury, or any other fluid, be poured into a tube of glass, bent in the form of =U=, and open at both ends, it will rise to the same height in both...

=139. Nature of Ozone.=--During the action of a powerful electric machine, and in the decomposition of water by the voltaic battery, a peculiar odour is perceptible, which is co...

In the pursuits and investigations of the science of Meteorology, which is essentially a science of observation and experiment, instruments are required for ascertaining, 1. the...