Chapter 4

+------------+-----------+-----------+ | | | | | | Low Water | | | Miles from |Level below| High Water| | Lake | Chicago | above Low | | Michigan. | Datum. | Water. | | | | | ------------------------------+------------+-----------+-----------+ | | | | | | ft. | ft. | Lake Michigan | | | 4.7 | Lake Joliet | 40 | 77 | 5 to 6 | Kankakee River | 51.30 | 93.70 | 18 to 20 | Morris | 61 | 100.3 | 21 | Marseilles | 77 | 102.8 | 4 to 5 | Ottawa | 84.5 | 132.1 | 26 | La Salle | 100.3 | 146.6 | 28 | Hennepin | 115.8 | 148.7 | 25 | Peoria | 161.4 | 151.3 | 21 | Mouth of the Illinois | 325 | 172.4 | 20 | | | | | ------------------------------+------------+-----------+-----------+

The project in contemplation provides that the depth of the canal as far as Lake Joliet (which is about six miles long) shall be not less than 22 ft., and on to La Salle not less than 14 ft. at first, with facilities to increase it to 22 ft. Beyond La Salle to the mouth of the Illinois, dredging and flushing by the large volume of water pouring in from Lake Michigan would make and maintain ultimately a similar depth.

As it appears recognized that the sewage channel of Chicago must be 15 ft. deep, and as provision is now being made all over the great lake system for vessels drawing 20 ft. of water, a comparatively small additional outlay would provide for a channel available for the largest lake vessels. It is claimed that by the co-operation of the Chicago municipality and the general government--the latter to advance a sum of not less than $50,000,000--a ship (and sanitary) canal 22 ft. deep could be made from the lake to Joliet, extended thence to Utica, 20 ft. deep, and from there to the Mississippi, 14 ft. deep.

That such a work would vastly enhance the commerce, not only of Chicago, but of the whole section of the country through which the canal would pass, admits of but little doubt, and probably the outlay would be justified by results similar to those achieved with other great canal works and rectified rivers in the United States.

The following figures, showing the tonnage carried in 1888-89, give some idea of the volumes of water-borne traffic in America:

Tons. Detroit River 19,099,060 Erie Canal 5,370,369 Sault Ste. Marie 7,516,022 Welland Canal 828,271 St. Lawrence Canal 1,500,096 Mississippi to New Orleans 3,177,000 " below St. Louis 845,000 Ohio 2,236,917 Chicago Canal and lake 11,029,575

Except on the Mississippi, it may be reckoned that navigation is closed by ice during five months a year. It may be mentioned, by way of comparison, that the traffic on the Suez Canal during the year 1888-89 was 6,640,834 tons.

One very interesting point in connection with this work is the effect that the diversion of so large a body of water from the lakes will have upon their _regime_. At least 10,000 cubic feet a second would be taken from Lake Michigan and find its way into the Mississippi; this is approximately 4½ per cent. of the total amount that now passes through the St. Clair River and thence over Niagara.

The following table gives some particulars of the great lakes and the discharge from them:

+----------+-------+--------+----------------------- | | | |Cubic Feet per Second. |Elevation |Area of| Area of+-------+-------+------- | above | Basin,| Lake, | | | Lake. |Mean Tide.| Square| Square| Rain- |Evapo- | Dis- | Feet. | Miles.| Miles.| fall. |ration.|charge. | | | | | | ---------------+----------+-------+--------+-------+-------+------- | | | | | | Superior | 601.78 | 90,505| 38,875 |187,386| 34,495| 80,870 Huron and Mich.| 581.28 |121,941| 50,400 |262,964| 66,754|216,435 Erie | 572.86 | 40,298| 10,000 | 96,654| 13,870|235,578 Ontario | 246.61 | 31,558| 7,220 | 75,692| 10,568|272,095 | | | | | | ---------------+----------+-------+--------+-------+-------+-------

The average variation in level of the lakes is from 18 in. to 24 in. during the year, and the range in evaporation from year to year is also very considerable; thus the evaporation per second on Huron and Michigan, as given in the table above, is nearly 67,000 ft., but the figures for another year show nearly 89,000 ft. per second, which would represent a difference of 6½ in. in water level. As a discharge of 10,000 cubic feet a second into the new canal would lower the level of these two lakes by 2.87 in. in a year, it follows that the difference between a year of maximum and one of minimum evaporation is more than twice as great as would be required for the canal, and even under the most unfavorable conditions the volume taken from the whole chain of lakes would not lower them an inch.

When the variations in level due to different causes--rain, wind, and evaporation being the chief--are taken into consideration, the effect of 10,000 cubic feet a second abstracted would probably not be noticeable. That this would be so is the opinion, after careful investigation, of many eminent American engineers. On the other hand there is a similar unanimity of opinion as to the advantages that would be obtained in the condition of the Mississippi by adding to it a tributary of such importance as the proposed canal.--_Engineering_.

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N.F. BURNHAM AND HIS LIFE WORK.

By W.H. BURNHAM.

The inventor and patentee of all water wheels known as the Burham turbine died from Bright's disease of the kidneys at his home, York, Pa., Dec. 22, 1890, aged 68 years 9 months and 9 days. He was born in the city of New York, March 13, 1822, and was of English-Irish and French descent. His father was a millwright and with him worked at the trade in Orange county, N.Y., until he was 16 years old. He then commenced learning the watchmakers' business, which he was obliged to relinquish, after three years, on account of his health. He then went to Laurel, Md., in 1844, and engaged with Patuxent & Co. as mercantile clerk and bookkeeper. In 1856 he commenced the manufacture of the French turbine water wheel. In 1879 he sold out his Laurel interests, went to New York and commenced manufacturing his own patents. On May 22, 1883, he founded the Drovers' and Mechanics' National Bank of York, and was elected its first president, which position he held at the time of his death. In 1881, with others, he built the York opera house, at a cost of $40,000. He was a Knight Templar, and past master of the I.O.O.F., and past sachem of Red Men.

He was the oldest turbine wheel manufacturer living, having been actually engaged in the manufacture of turbines since 1856. He first made and sold the French Jonval turbine, which was then the best turbine made, but being complicated in construction, it soon wore out and leaked. From the experience he had from this wheel he invented and patented Feb. 22, 1859, his improved Jonval turbine, which was very simply constructed and yielded a greater percentage of power than the French Jonval turbines. Hundreds of these improved wheels, which were put in operation between the years 1859 and 1868, are still in use. (We show no cut of this wheel, but it had four chutes instead of six, as shown in March 24, 1863, patent.)

The first wheel (72 inch) made after the patent was granted was sold to Brightwell & Davis, Farmville, Va., and put into their flour mill under six feet head. In 1870, Brightwell & Davis sold their mill to Scott & Davis. Afterward G.W. Davis owned and operated the mill and put in one 1858 patent "New Turbine." In 1889 the Farmville Mill Company bought and remodeled the mill to roller process and required more power than the old 1856 Jonval turbine and 1868 "New Turbine" would yield, and on Aug. 30, 1889, sold the Farmville Mill Company two 54 inch new improved Standard turbines to displace the two old wheels. In 1860 he commenced experimenting with different forms of buckets and chutes, and used six chutes instead of four as first made, and was granted patent March 24, 1863.

This addition of chutes proved beneficial, as the wheel worked better with the gates partly opened than it did with four chutes. His next invention was granted him Dec. 24, 1867, which he called Burnham's improved central and vertical discharge turbine.

This improvement consisted in making the guide blade straight on the outside (instead of rounding, as then made by all others), from inner point back to bolt or gudgeon, and thick enough at the latter point to let water pass without being obstructed by said bolt and the arrangement for shifting the water guides. Two 42-inch wheels of this pattern were built and put into operation, but they soon commenced leaking water and became troublesome on account of the many small pieces of castings and bolts, and were abandoned as worthless. There are several manufacturers of this style of wheel that advertise them as "simple and durable." Such a complicated case with twelve chutes cannot be made to operate unless by a large number of castings, bolts and studs. With these adjustable water guides, one of the objects was obtained. Admitting the water to the wheel through chutes corresponding in height to the outer edge of buckets exposed, but not placing the water against the face of the buckets at right angles with the center of the wheel, except when the guide blades were full opened, for as the guides are changed so is the current of the water likewise changed.

After making several differently constructed wheels and testing them a number of times, he selected the best one and obtained a patent for it March 3, 1868, and called it "new turbine," which he still further improved and patented May 9, 1871. This "new turbine" consisted of the former improved Jonval wheel, hub and buckets, with a new circular case and new form of chutes, having a register gate entirely surrounding the case and having apertures corresponding to those in the case for admitting water to the wheel. This register gate was moved by means of a segment and pinion.

This "new turbine" soon gained for itself a reputation enjoyed by no other water wheel. It was selected by the United States Patent Office, and put at work in room 189, to run a pump which forces water to the top of the building. It was likewise selected by the Japan commission when they were in this country to select samples of our best machines. He continued making the 1868 patent and improved in 1871 "new turbine" but a few years, for as long as he could detect a defect in the wheel, case or gate, he continued improving and simplifying them, and in 1873 he erected a very complete testing flume, also made a very sensitive dynamometer, it having a combination screw for tightening the friction band, which required 100 turns to make one inch, and commenced making and experimenting with different constructed turbines. He made five different wheels and made over a hundred tests before he was satisfied. Application was then made for a patent, which was granted March 31, 1874, for his "Standard turbine."

This "Standard turbine" was a combination of his former improvements, with the cover extending over top of the gate to prevent it from tilting, and an eccentric wheel working in cam yoke to open and close the gate.

Thousands of Standard turbines are to-day working and giving the best satisfaction, and we venture to say that not one of the Standard turbines has been displaced by any other make of turbine, which gave better results for the water used. In 1881 he again commenced experimenting to find out how much water could be put through a wheel of given diameter. After making and testing several wheels it was found that the amount of water with full gate drawn named in tables found in Burnham Bros.' latest catalogue for each size wheel yielded 84 per cent. and that the water used with 7/8 gate drawn yielded the same percentage (84), or with 3/4 gate 82 per cent., 5/8 gate 79, and 1/2 gate 75 per cent. A patent for the mechanism was applied for and granted March 27, 1883, and named Burnham's Improved Standard Turbine.

It was found that the brackets with brass rollers attached, to prevent the gate from rising and tilting and rubbing the curb, soon wore and allowed the gate to rub against the curb, and he experimented with several devices of gate arms. While so engaged he found that the great weight of water on the top of the cover sprang it, causing the sleeve bearing on the under side of the cover to be thrown out of place, and the gate pressed so hard against the case that it was almost impossible to move it, and after thoroughly testing with the different devices of gate arms, application was made and patent granted for adjustable gate arms, also for the new worm gate gearing May 1, 1888, and named Burham's new improved standard turbine.

This he improved and patented May 13, 1890, to run on horizontal shaft.

In the year 1872 he had two patents granted him for improvement in water wheels, but never had any wheels built of that pattern. After completing and patents granted for his new improved Standard turbine, he was perfectly satisfied, and often remarked, "I cannot improve on my register gate turbine any more, as it is as near perfection as can be made," and he was fully convinced, for the past year he was experimenting with a cylinder gate turbine, and patent was granted Oct. 21, 1890. Previously he had made a 24-inch wheel, which was tested Aug. 14, 1890, at Holyoke testing flume, and gave fair results, and at the time of his demise he was having made a new runner for the cylinder gate turbine, which we will complete and have tested. His idea was to have us manufacture and sell register and cylinder gate turbines. His inventive powers were not confined to water wheels, for on Feb. 23, 1886, patents were granted him for automatic steam engine, governor and lubricating device. We also remember in the year 1873 or 1874, when his mind was occupied with his "Standard turbine," he was hindered by some device used now on locomotives of the present construction (what it was we are unable to say), but when draughting at his water wheel, would conflict the two, and by his invitation we wrote to a prominent locomotive builder and had him examine the drawings, which he had not fully completed, and sold same to him. Of this we only have a faint recollection, but do recollect his saying: "Well, that is off my mind now, and I can devote it to the finishing of my new wheel."--_American Miller_.

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ALTERNATE CURRENT CONDENSERS.

At a recent meeting of the Physical Society, London, Mr. James Swinburne read a paper on alternate current condensers. It is, he said, generally assumed that there is no difficulty in making commercial condensers for high pressure alternating currents. The first difficulty is insulation, for the dielectric must be very thin, else the volume of the condenser is too great. Some dielectrics 0.2 mm. thick can be made to stand up to 8,000 volts when in small pieces, but in complete condensers a much greater margin must be allowed. Another difficulty arises from absorption, and whenever this occurs, the apparent capacity is greater than the calculated. Supposing the fibers of paper in a paper condenser to be conductors embedded in insulating hydrocarbon, then every time the condenser is charged the fibers have their ends at different potentials, so a current passes to equalize them and energy is lost. This current increases the capacity. One condenser made of paper boiled in ozokerite took an abnormally large current and heated rapidly. At a high temperature it gave off water, and the power wasted and current taken gradually decreased.

When a thin plate of mica is put between tin foils, it heats excessively; and the fall of potential over the air films separating the mica and foil is great enough to cause disruptive discharge to the surface of the mica. There appears to be a luminous layer of minute sparks under the foils, and there is a strong smell of ozone. In a dielectric which heats, there may be three kinds of conduction, viz., metallic, when an ordinary conductor is embedded in an insulator; disruptive, as probably occurs in the case of mica; and electrolytic, which might occur in glass. In a transparent dielectric the conduction must be either electrolytic or disruptive, otherwise light vibrations would be damped. The dielectric loss in a cable may be serious. Calculating from the waste in a condenser made of paper soaked in hot ozokerite, the loss in one of the Deptford mains came out 7,000 watts. Another effect observed at Deptford is a rise of pressure in the mains. There is as yet no authoritative statement as to exactly what happens, and it is generally assumed that the effect depends on the relation of capacity to self-induction, and is a sort of resonator action. This would need a large self-induction, and a small change of speed would stop the effect. The following explanation is suggested. When a condenser is put on a dynamo, the condenser current leads relatively to the electromotive force, and therefore strengthens the field magnets and increases the pressure.

In order to test this, the following experiment was made for the author by Mr. W.F. Bourne. A Gramme alternator was coupled to the low pressure coil of a transformer, and a hot wire voltmeter put across the primary circuit. On putting a condenser on the high pressure circuit, the voltmeter wire fused. The possibility of making an alternator excite itself like a series machine, by putting a condenser on it, was pointed out. Prof. Perry said it would seem possible to obtain energy from an alternator without exciting the magnets independently, the field being altogether due to the armature currents. Mr. Swinburne remarked that this could be done by making the rotating magnets a star-shaped mass of iron. Sir W. Thomson thought Mr. Swinburne's estimate of the loss in the Deptford mains was rather high. He himself had calculated the power spent in charging them, and found it to be about 16 horse power, and although a considerable fraction might be lost, it would not amount to nine-sixteenths. He was surprised to hear that glass condensers heated, and inquired whether this heating was due to flashes passing between the foil and the glass. Mr. A.P. Trotter said Mr. Ferranti informed him that the capacity of his mains was about 1/3 microfarad per mile, thus making 2-1/3 microfarads for the seven miles. The heaping up of the potential only took place when transformers were used, and not when the dynamos were connected direct. In the former case the increase of volts was proportional to the length of main used, and 8,500 at Deptford gave 10,000 at London.

Mr. Blakesley described a simple method of determining the loss of power in a condenser by the use of three electrodynamometers, one of which has its coils separate. Of these coils, one is put in the condenser circuit, and the other in series with a non-inductive resistance r, shutting the condenser. If a_{2} be the reading of a dynamometer in the shunt circuit, and a_{3} that of the divided dynamometer, the power lost is given by r (Ca_{3} - Ba_{2}) where B and C are the constants of the instruments on which a_{2} and a_{3} are the respective readings. Prof. S.P. Thompson asked if Mr. Swinburne had found any dielectric which had no absorption. So far as he was aware, pure quartz crystal was the only substance. Prof. Forbes said Dr. Hopkinson had found a glass which showed none. Sir William Thomson, referring to the same subject, said that many years ago he made some tests on glass bottles, which showed no appreciable absorption. Sulphuric acid was used for the coatings, and he found them to be completely discharged by an instantaneous contact of two balls. The duration of contact would, according to some remarkable mathematical work done by Hertz in 1882, be about 0.0004 second, and even this short time sufficed to discharge them completely.

On the other hand, Leyden jars with tinfoil coatings showed considerable absorption, and this he thought due to want of close contact between the foil and the glass. To test this he suggested that mercury coatings be tried. Mr. Kapp considered the loss of power in condensers due to two causes: first, that due to the charge soaking in; and second, to imperfect elasticity of the dielectric. Speaking of the extraordinary rise of pressure on the Deptford mains, he said he had observed similar effects with other cables. In his experiments the sparking distance of a 14,000 volt transformer was increased from 3/16 of an inch to 1 inch by connecting the cables to its terminals. No difference was detected between the sparking distances at the two ends of the cable, nor was any rise of pressure observed when the cables were joined direct on the dynamo.

In his opinion the rise was due to some kind of resonance, and would be a maximum for some particular frequency. Mr. Mordey mentioned a peculiar phenomenon observed in the manufacture of his alternators. Each coil, he said, was tested to double the pressure of the completed dynamo, but when they were all fitted together, their insulation broke down at the same volts. The difficulty had been overcome by making the separate coils to stand much higher pressures. Prof. Rucker called attention to the fact that dielectrics alter in volume under electric stress, and said that if the material was imperfectly elastic, some loss would result. The president said that, as some doubt existed as to what Mr. Ferranti had actually observed, he would illustrate the arrangements by a diagram. Speaking of condensers, he said he had recently tried lead plates in water to get large capacities, but so far had not been successful.