612 SCIENTIFIC RECORD FOR 1883. 



In 4 hours- only G and in 4£ hours only 4 lamps were maintained. The 

 12 cells consumed 0.912 kilogram of zinc or 0.076 per cell for the five 

 hours. (C. B., March, April, 1883, xcvi, 787, 1048; J. Soc. Tel. JEng., 

 KII, 016.) 



Hallock has investigated the conditions of variation in the electro- 

 motive force of the Smee battery, especially that due to polarization. 

 He concludes, first, the accepted view that the variations in E. M. F. of 

 the Smee battery are due to variations of hydrogen polarization on the 

 platinum plate is correct; second, the electromotive force of polariza- 

 tion is by no means independent of the substance of the electrodes; 

 third, we cannot calculate the polarization from the thermo-chemical 

 equivalents; and, fourth, the electromotive force of polarization can be 

 raised considerably above that necessary to produce a visible evolution 

 of gas. (Am, J. ScL, April, 1883, III, xxv, 268.) 



Kittler has given the name " normal element" to a cell composed of 

 amalgamated pure" zinc in dilute sulphuric acid of specific gravity 1.075 

 at 18° C, and of pure copper in concentrated copper sulphate solution of 

 specific gravity 1.190 to 1.200. (Nature, February, 1883, xxvn, 325.) 



Barker has devised a new form of Daniell cell to be used as a stand- 

 ard. It consists of two bottles having tubulures at the side near the 

 bottom, closed by rubber corks through which the ends of a glass stop- 

 eock pass. One of these bottles contains the zinc rod passing through 

 a cork in the neck and immersed in a saturated solution of zinc sul- 

 phate. The other bottle contains the copper rod immersed in saturated 

 •copper-sulphate solution. The advantages claimed for the cell are its 

 uniformity, no evaporation taking place, and no change in the liquids 

 by the action of the battery or by diffusion. When not in use the cock 

 .communicating between the bottles is kept closed. (Proc. Am, Phil 

 JSoc, January, 1883, XX, 649.) 



Von Waltenhofen has claimed for Pfaundler, of Innsbruck, priority 

 in producing continuous-current machines. In 1867 Kravogl showed at 

 the Paris Exposition his electric motor. This consisted of a series of 

 coils forming a hollow ring which rotated about a horizontal axis. 

 Within it is inclosed a curved cylindrical rod, which, by its weight, 

 tends to take the lowest position, but is kept suspended in a raised 

 position by currents in the coils. The reaction of the attraction rotates 

 the ring. Pfaundler the same year proposed to apply Siemens' prin- 

 ciple to it and get electric currents from mechanical work. This he 

 tried and successfully effected three years later, as he states in a letter 

 dated February 11, 1870. (Nature, March, 1883, xxvn, 517.) 



3. Electrical Measurements. 



Mercadier and Vaschy have published a paper on the dimensions of 

 electric and magnetic magnitudes, in which, among other questions, 

 they consider the influence of the surrounding medium upon electro- 

 dynamic induction, and conclude from their own experimental investi- 



