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THE POPULAR SCIENCE MONTHLY. 



a wreath was placed at its feet. M. Tresca 

 made the memorial address, and claimed for 

 Papin the distinction of having been the in- 

 ventor of the first steam-engine. Excur- 

 sions were made to various places of inter- 

 est, among them the strata of Thenay, where 

 Abbe Bourgeois thinks he has discovered 

 relics of tertiary man, and the Celtic cav- 

 erns of Troo. 



Discussions at the Electrical Conference. 



— An Electrical Conference sat in Philadel- 

 phia, in connection with the Electrical Ex- 

 hibition, during the second week in Septem- 

 ber, and was attended by about one hundred 

 and seventy-five American and foreign dele- 

 gates. Professor Simon Newcomb opened 

 the session with an address of welcome, aft- 

 er which the President of the Conference, 

 Professor Henry A. Rowland, presented in 

 his official address the subjects of the in- 

 terdependence of applied and pure science, 

 some of the questions still open in electrical 

 science, and the need of more careful train- 

 ing in the theory of electricity in technical 

 schools. The meetings of the Conference 

 were continued, with discussions of the best 

 methods of extending our knowledge of 

 atmospheric electricity and earth-currents, 

 and any possible relation that may exist be- 

 tween them and the weather, by Professor 

 Abbe ; the question of the establishment of 

 a Bureau of Physical Standards, under the 

 supervision of the Government, by Professor 

 Snyder and other members of the Confer- 

 ence; the theory of the dynamo-electric ma- 

 chine, by Professor Rowland, with remarks 

 by Professor Fitzgerald, of Dublin, and Pro- 

 fessor Silvanus P. Thompson ; the electrical 

 transmission of energy, by Professor Nipher, 

 of Washington University, St. Louis ; stor- 

 age-batteries, by Mr. W. H. Prcece and Pro- 

 fessor Dewar ; and long-distance telephony. 

 On the last subject Mr. T. D. Lockwood 

 mentioned earth-currents, atmospheric elec- 

 tricity, imperfect contacts, and leakage from 

 other lines, together with electro-static and 

 electro-dynamic induction, as causes of the 

 noises on telephone lines. Long lines are 

 more subject to these troubles than short 

 ones, and north and south lines than east 

 and west ones. Sometimes one end of the 

 line will be noisy and the other end quiet, 

 as between Chicago and Milwaukee, where 



it is quiet at the Chicago end and noisy at 

 Milwaukee, Lines subject to nearly uniform 

 leakage are more quiet than well-insulated 

 lines, lines near the sea than inland ones, 

 and lines of small wire than lines of large 

 wire. Many of the sources of disturbance 

 may be got rid of by providing a metal- 

 lic return-circuit, hung parallel to the first 

 circuit and similarly to it. When a long 

 air-line ends in a short underground cable, 

 the person at the end of the cable can make 

 himself heard, while the person at the end 

 of the long line can not. Captain 0. E. 

 Michaclis recommended the study of iron, 

 copper, brass, etc. — the metals used in struct- 

 ures — by electrical or magnetic methods — 

 with a view to finding means of discoverin"' 

 defects and weaknesses. On the electrical 

 protection of houses, Professor Rowland 

 spoke well of the conductors enveloping the 

 house as if they were a cage : thus, it is 

 well to have the rods run down the four cor- 

 ners of the house and across the angles of 

 the roof, joining at the top, so as to form 

 the skeleton of the cage. Additional rods 

 may also be run down the sides of the house. 

 The rods must be well grounded, otherwise 

 they will be worse than useless. Twisted 

 rods are not recommended. Small rods, 

 bearing points, should rise from the main 

 rods at different points on the roof. 



Tlie Association of Official Cliemists.— 



An Association of Official Chemists of the 

 United States was organized during the 

 meeting of the American Association. Chem- 

 ists of the Department of Agriculture, State 

 agricultural societies, and boards of official 

 control, are eligible to membership in the 

 Association, and each of the organizations 

 thus represented is entitled to one vote on 

 all matters on which the society may ballot, 

 while other chemists are invited to attend 

 the meetings and take part in the discus- 

 sions, without having the right to vote. 

 Three standing committees were appointed 

 — on the determination of phosphoric acid, 

 nitrogen, and potash — who will distribute 

 samples for comparative work, and report 

 the results at the annual or at special meet- 

 ings. The following officers of the Asso- 

 ciation were elected : President, Professor 

 S. W. Johnson, of Connecticut ; Vice-Presi- 

 dent, Professor II. C. White, of Georgia ; 



