December 23, 1898.] 



SCIENCE. 



899 



first time, a method for the rational design 

 of alternating current transformers. Our 

 knowledge of this important piece of ap- 

 paratus has, up to this time, consisted in 

 part of a precise and complete knowledge 

 of its behavior and in part of a keen sense 

 of propriety in design on the part of the 

 more progressive practical electricians ; but 

 a rational method for correlating the 

 various items in the design with a view to 

 the production of a transformer which shall 

 at once meet prescribed conditions in the 

 best possible way we have not had. The 

 method has rather been to assume (on 

 paper) a large number of alternative de- 

 signs, to calculate the action of each in 

 detail, and to adopt that design which best 

 meets all the requirements. 



It is only fair to the practical electricians 

 to say that Mr. Carter's results will not in- 

 validate much, if any, of their more recent 

 work for the reason that the old method of 

 designing is fully adequate if enough labor 

 is devoted to it, and this condition has been 

 abundantly satisfied. Teachers of electrical 

 engineering, on the other hand, may hail Mr. 

 Carter's paper with satisfaction as affording 

 further occasion for the application of ele- 

 gant mathematics — not used in practice ! 



UNDERGROUND ELECTRIC CURRENTS IN NEW 

 YORK CITY. 



There is a serious and growing trouble 

 with gas and water pipes, due to hurtful 

 electrolytic action of underground electric 

 currents, mainly from trolley lines. Mr. 

 A. A. Kundson has recently reported to 

 the American Institute of Electrical En- 

 gineers the results of an electrical survey 

 of New York City and of the Brooklyn 

 Bridge. He finds the conditions at the 

 anchorages to be such as have been known 

 to do serious hurt to water pipes, although, 

 as he points out, the action upon the mas- 

 sive iron anchors to which the suspending 

 cables are attached may be very slight, be- 



cause of their being surrounded by concrete 

 in which there is a certain amount of free 

 lime and a definite lack of those chemical 

 salts which conduce to destructive electro- 

 lytic action. The matter is, however, suf- 

 ficiently serious to be taken into deliberate 

 consideration, as it is unlikely that the an- 

 chors can withstand the present action for 

 a long series of years. 



HIGH-VOLTAGE POWER TRANSMISSION. 



Mb. Chas. F. Scott has recently pre- 

 sented to the American Institute of Elec- 

 trical Engineers the results of some unique 

 tests of high voltage transmission lines. 

 These tests have been made partly in the 

 laboratory by Mr. Scott and partly upon 

 the operating plant at Telluride, Colorado, 

 by Mr. Mershon. One of the most interest- 

 ing of the results is that the loss of power 

 due to dischai'ge between the two. wires 

 (outgoing and returning wires) begins to 

 be excessive when the e. m. f. reaches about 

 50,000 to 60,000 volts. This kind of loss 

 was one of the uncertainties which con- 

 fronted the engineers who installed the 

 now classical plant which transmitted 

 power (at 30,000 volts) from Schaffhausen 

 to the Electrical Exhibition at Frankfort 

 in 1891, and these tests of Mr. Scott are 

 the fii'st to show just when this loss be- 

 comes considerable under practical condi- 

 tions. The highest e. m. f. at present used 

 in power transmission is 40,000 volts at the 

 Provo plant of the Telluride Power Trans- 

 mission Company in Utah, which transmits 

 power to a distance of thirty-five miles. 

 W. S. F. 



NOTES ON INORGANIC CHEMISTRY. 

 The current number of Nature contains a 

 full abstract of a paper read by Professor 

 W. C. Eoberts-Austen at the Institution of 

 Civil Engineers on the extraction of nickel 

 from its ores by the Mond process. This 

 process is an entirely new departure in 



