80 



SCIENCE 



[Vol. V., No. 103. 



maintaining sixteen thousand lamps, even if 

 only a fifth part would be in use at one time, 

 and also for supplying power to small motors, 

 is still in doubt. At present power is not sup- 

 plied. It was intended that the system should 

 be used for supplying power in the day-time, 

 and light at night. 



Leaving the central station in New York, 

 Dr. Hagen then proceeds to inspect the village 

 plant at Roselle, N.J., and studies this new 

 and promising development of electric light- 

 ing, of which there are already several exam- 

 ples in the United States, notably that at 

 Brockton, Mass. At Roselle three so-called 

 two-hundred-and-fifty-light machines are in- 

 stalled, which are driven by a thirty-five-horse 

 power engine. The price is a dollar per thou- 

 sand candle hours (kerzenstunde) . The elec- 

 tromotive force of the machine is 320 volts, 

 and the current per lamp ^^ of an ampere. 

 The number of lights in practical use is 800. 

 The greatest distance to which the system is 

 carried at present at Roselle is about 4,500 

 feet. 



The writer then discusses the s}*stem of the 

 U. 8. electric-lighting company, which uses the 

 Weston machine and the various modifications 

 of the Maxim lamp, also the Bernstein elec- 

 tric-lighting system. The author closes his 

 interesting and valuable discussion of the va- 

 rious systems of incandescent lighting by a 

 resume of the measurements made at Munich 

 and at Paris, and an analysis of the cost of 

 the Edison system. In this chapter will be 

 found statements of the cost of this system 

 from various agents of mills which are lighted 

 by the incandescent light. So man}' elements 

 peculiar to each installation enter into this 

 analysis, that it is impossible to say in general 

 what the cost of electric lighting is. Each 

 business-man must decide for himself whether 

 it is economical, on the whole, for him to use 

 the electric light or not. In man}- cases there 

 is decided advantage, and even economy, in 

 its employment. 



Dr. Hagen details in a graphic wa}' the hopes 

 raised by the various storage-batteries, and the 

 leaden thoughts of those who have had their 

 hopes dispelled. These batteries at present 

 are useful only in laboratories. 



The third portion of Dr. Hagen' s treatise is 

 devoted to arc-lighting, and in it the systems 

 of Brush, of Weston, and of Thomson-Hous- 

 ton, are fully described. The treatise closes 

 with a short essa}' on the dangers of electric 

 lighting, and a copy of the regulations adopted 

 by the board of fire-insurance inspectors in 

 Boston. 



NOTES AND NEWS. 



Mr. Henry Lomb of Kochester, N.Y., has of- 

 fered, through the American public health associa- 

 tion, the sum of $2,800, to be awarded as first and 

 second prizes for papers on the following subjects : — 



1°. Healthy homes and foods for the working- 

 classes: first prize, $500; second prize, $200. Es- 

 says to be of a practical character, devoid, as far as 

 possible, of scientific terms. They must be within 

 the scope and understanding of all classes, and de- 

 signed especially for a popular work. 2°. The sani- 

 tary conditions and necessities of schoolhouses and 

 school-life : first prize, $500; second prize, $200. 

 3°. Disinfection and individual prophylaxis against 

 infectious diseases: first prize, $500; second prize, 

 $200. 4°. The preventable causes of disease, injury, 

 and death, in American manufactories and work- 

 shops, and the best means and appliances for pre- 

 venting and avoiding them : first prize, $500; second 

 prize, $200. 



All essays written for the above prizes must be in 

 the hands of tbe secretary, Dr. Irving A. Watson, 

 Concord, N.H., on or before Oct. 15, 1885. It is ex- 

 pected that arrangements can be made to have these 

 essays widely distributed to the public, and to the 

 persons most interested in the respective subjects 

 in the United States. The American public health 

 association earnestly appeals to those able to com- 

 pete, to take part in this work, which, it is believed, 

 will do much to augment the health, comfort, and 

 happiness of the people. 



— In addition to the issue of its regular publica- 

 tions, the Leander McCormick observatory of the 

 University of Virginia (Professor Ormond Stone, di- 

 rector) has begun the issue of a series of circulars, 

 of which the number just received contains the ele- 

 ments and ephemeris of the small planet Barbara No. 

 234. The elements and perturbations by Jupiter 

 were computed by Mr. S. M. Barton ; and the pertur- 

 bations by Saturn and the ephemeris, by Mr. F. P. 

 Leavenworth. 



— The quinquennial prize offered by the Belgian 

 government for researches in mathematical and 

 physical science has been awarded to Professor Le 

 Paige of the University of Liege, for his investiga- 

 tions in the higher geometry, and especially for 

 those relating to lines and surfaces of the third 

 order. 



— The valuable Cohen collection of Egyptian an- 

 tiquities, which has recently been acquired by the 

 Johns Hopkins university, will be of great interest, 

 not only for art, but for the historical study of the 

 customs and laws of Egypt. It was begun in 1832 

 by Col. M. I. Cohen, during his travels in Egypt, 

 and consists of six hundred and eighty-nine objects, 

 procured mainly in the localities where they were 

 originally discovered. A number of objects, how- 

 ever, belonged to the famous collection of Mr. Salt, 

 her Majesty's consul in Egypt, which was sold in 

 1835. The collection consists chiefly of small works 

 illustrating the history of the minor arts in Egypt 



