March 22, 1889.] 



SCIENCE. 



217 



the Otto, is well known in this country. A mixture of gas and air 

 is admitted into the cylinder and ignited, the explosion giving 

 the motive power. The arrangement is such that the engine re- 

 ceives one impulse in every two revolutions ; so, in order to get a 

 steady motion, an extremely heavy fly-wheel, or a countershaft 

 carrying a fly-wheel, is necessary. Another of the gas-engines, the 

 Atkinson, is of rather remarkable design. There are four strokes 

 of the piston to one revolution of the fly-wheel, and these strokes 

 are of varying length. The stroke which takes the charge into the 

 cylinder is 6.3 inches ; the next stroke compresses the charge, and 

 is 5 inches in length, the charge being thus compressed into a space 

 of 1.3 inches. The compression being effected, ignition takes 

 place, giving the working stroke, which is 11. 13 inches in length. 

 This is followed by the exhaust stroke, which sweeps the products 

 of combustion out, and is 12.4 inches in length. The cylinder is 9.5 

 inches in diameter. The third of the gas-engines, the Griffin, dif- 

 fers from the other two in several particulars. An impulse is given 

 to the crank-shaft for every revolution and a half. The tests were 

 made by Professor A. C. W. Kennedy, Dr. John Hopkinson, and 

 Mr. Beauchamp Tower. Taking first the Atkinson engine, they 

 found that the gas consumed per indicated horse- power was 18.8 

 cubic feet, and per brake horse-power 22.1 cubic feet per hour. 

 The gas used for ignition was 4.5 cubic feet per hour, making a 

 total per brake horse-power of 22.6 cubic feet per hour. The en- 

 gine ran smoothly and with regularity. The mechanical efficiency 

 ■ of the engine was 85 per cent, and 25.5 per cent of the whole of 

 the heat generated was converted into work. The Otto engine 

 used 27.4 cubic feet of gas per hour for an available horse-power. 

 The Griffin engine used 28 feet per hour for an available horse- 

 power. These figures show, that, as far as the cost of gas is con- 

 cerned, it is more economical to use it to drive an engine, and use 

 the power developed for electric lighting, than to burn it directly. 

 For instance : if we take 25 cubic feet of gas per hour as the aver- 

 age amount consumed per horse-power by a gas-engine, then we 

 have, by burning direct, 5 i6-candle-power gaslights ; with gas- 

 engine and dynamo, 12 i6-candle-power electric lights. There 

 are at present, however, so many additional expenses incident to an 

 isolated electric plant, — interest, depreciation, breakage, attend- 

 ance, etc., — that it is cheaper to use the gas directly. At the 

 same time, the figures given suggest possibilities. The fourth en- 

 gine tested was a Davy-Paxman steam-engine of about twenty 

 horse-power. This gave some remarkable results. It is a com- 

 pound engine, the cylinders being 5.24 and 8.98 inches in diameter, 

 and the stroke 14 inches, the pressure used being 190 pounds. 

 The result of one of the trials was an available horse-power for 

 2.08 pounds of coal per hour, — a remarkable result, considering 

 the size of the engine. These results show, that, as far as cost of 

 fuel alone is considered, a horse-power hour from a gas-engine, 

 with gas at $1.50 per thousand feet, would cost 3.75 cents; and 

 from a Davy-Paxman engine, with coal at $4 per ton, .8 of a cent. 



Accumulators. — Judge Coxe has just rendered a decision in 

 the United States Circuit Court for the southern district of New 

 York, in which the Faure patent for improvements in secondary 

 batteries or accumulators is held to cover any secondary battery in 

 which an electrode is used having the so-called active material ap- 

 plied in the form of a paint, paste, or cement. The suit is entitled 

 " The Electrical Accumulator Company vs. Julien Electric Com- 

 pany." The field for accumulators is very large, as shown by the 

 fact that there are to-day no less than eight or ten companies en- 

 gaged in that business. Among them are the Electrical Accumu- 

 lator Company, owning the Faure patents, and the Julien, Gibson, 

 Woodward, Pumpelly, and Macrson Companies, all of whose bat- 

 teries, the Accumulator Company claims, are tributary to the Faure 

 invention. In anticipation of a favorable decision, the Electrical 

 Accumulator Company has already built a street-car to be propelled 

 by means of batteries, and now has it on exhibition on Elkins & 

 Widener's Philadelphia Traction Road in West Philadelphia. Its 

 initial trip last Friday was a success, the car moving up a long 

 five-per-cent grade at the rate of seven miles an hour. Brill & Co., 

 West Philadelphia, are making six other cars to be completed in 

 April and May ; and the Electrical Accumulator Company is now 

 prepared to occupy extensively the electric street-car field. 



NOTES AND NEWS. 

 Dr. R. W. Shufeldt has moved from Fort Wingate, N.Mex., 

 to Washington, D.C., where he will continue in his scientific pur- 

 suits at the Smithsonian Institution. 



— The wind-pressure on the Forth bridge, or rather the effective 

 area of a bridge exposed to a wind-pressure striking the work at 

 different angles, was practically demonstrated by Mr. B. Baker, as 

 described in a late lecture before the Society of Arts, as follows : a 

 model of the bridge was made, and towed in water at different an- 

 gles to the stream ; the area of a flat board normal to the current 

 was then determined, which exerted the same drag as the model ; 

 this area was then taken as the effective area of the bridge for the 

 particular angle at which it was towed., 



— M. Alfred Binet of Paris, France, will contribute to The Open 

 Court (Chicago) of March 21 a paper on " Sensation and the Outer 

 World." The article is part of an unpublished essay upon " Ex- 

 ternal Perception," crowned by the Academic des Sciences Mo- 

 rales et Politiques. In the same number Professor Edward D. Cope 

 of Philadelphia will present some considerations upon ethical evolu- 

 tion, including a review of the extent and significance of the utili- 

 tarian doctrine of morals. The Open Court of March 28 will con- 

 tain an article by the German Sanscrit scholar, Professor H. 

 Oldenberg, on the " Discovery of the Veda." The disclosures that 

 this epoch-making event have led to, form the most interesting 

 chapter in all philological science. 



— The composition and evaporative power of Kansas coals have 

 been investigated by Professor E. H. S. Bailey and Professor L. I. 

 Blake, of the State University. The coal-measures that underlie 

 the eastern part of the State of Kansas are being developed at the 

 present time to a greater extent than ever before. With the in- 

 creased population of the State, the introduction of important man- 

 ufactories, and the extension of so many lines of railway, there is 

 naturally a greater demand for fuel, and a greater interest in its 

 economic supply. In the last " Report of the State Mine Inspec- 

 tor " (1887), there are mentioned about a hundred shafts, in the 

 different regions, where mining is actively carried on ; besides this, 

 there are innumerable places where coal is mined or stripped in a 

 small way to supply the local trade. The coal-beds seem to be di- 

 vided into several groups, the lowest being in the extreme south- 

 eastern part of the State. The coals depreciate in their steam- 

 producing powers from the south-eastern part of the State toward 

 the north and west. Professor Bailey finds they depreciate in the 

 amounts of fixed carbon in a similar order. 



— The Johns Hopkins Hospital will be opened to the inspection 

 of the public, before the reception of patients, during the week be- 

 ginning May 6, 1889. On Tuesday, May 7, at 11 o'clock in the 

 morning, there will be appropriate addresses in the main adminis- 

 tration building. Invitations to be present will be sent to the 

 authorities of the city and State, to those who have rendered special 

 services in promoting the plans of the hospital, to professors of 

 medicine and surgery, to the chief managers of other hospitals, and 

 to the representatives of the press. On Wednesday, May 8, be- 

 tween the hours of 12 and 6 o'clock, the buildings will be open to 

 the medical profession of Baltimore, Washington, and the State of 

 Maryland, to medical students, to the managers of the benevolent 

 institutions of Baltimore, to the ministers of all religious denomina- 

 tions, and to other persons whose pursuits have led them to take a 

 special interest in hospital-work. Cards of admission will be dis- 

 tributed in advance. On Thursday, May 9, and Friday, May 10, 

 between the hours of 12 and 6 o'clock, the public generally will be 

 invited to visit the hospital. Cards of admission may be obtained, 

 on the days named, at the entrance-gate of the hospital, Broadway. 

 On Saturday, May 11, the faculties of the various institutions in 

 Baltimore, the teachers of public and private schools of every kind, 

 the students of the Johns Hopkins University, the Baltimore City 

 College, the State Normal School, the Woman's College of Balti- 

 more, and the Eastern and Western Female High Schools, will be 

 admitted between the hours of 10 and 6 o'clock upon the presenta- 

 tion of tickets, which will be distributed in advance. The dispen- 

 sary will be opened for the treatment of out-door patients, Mon- 

 day, May 13, at 10 o'clock. The hospital will be opened soon 

 afterwards for the treatment of patients. 



