ELECTRICITY. 



239 



nations. Austria is understood to be in favor 

 of that step, but would not be in a hurry to 

 pronounce. Prussia is reported to be com- 

 pletely in accord with England, who ardently 

 desires the neutralization. Italy, who sees her 

 Eastern commerce increasing, is strongly dis- 

 posed to support the project. France and 

 Russia are of a contrary opinion. The former, 

 as the principal promoter of the now completed 

 works, is supposed to hope to obtain certain 

 privileges for the French ships which may 

 wish to make use of the canal ; and the latter, 

 who regards with a distrustful eye every road 

 which is opened toward the East, and of which 

 she is not mistress, is believed to entertain the 

 project if this channel is really accessible to 

 large steam-vessels of asking for a modifica- 

 tion of the treaties which regulate navigation 

 in the Bosporus and the Dardanelles. 



ELECTRICITY. Electro-magnetic Induc- 

 tion Machines. Mr. H. Wilde's invention has 

 been somewhat improved during the year by 

 his own efforts and those of others. One of the 

 practical difficulties in the use of his apparatus 

 was the generation of high internal heat in 

 large electro-magnetic machines by the rapid 

 magnetization and demagnetization of the arma- 

 tures. By means of a current of water circu- 

 lating in the hollow brass segments which 

 form part of the magnet-cylinder, this heat is 

 now so far reduced as to permit the machines 

 to be worked, for days and nights together, 

 without intermission, and without any sensible 

 diminution of the power of the current. It 

 has also been found that the current from one 

 small magneto - electric or electro - magnetic 

 machine is sufficient to excite simultaneously 

 the electro-magnets of several small machines. 

 In a number of S^-inch machines constructed 

 for the electro-deposition of copper on a large 

 scale, the currents from two of them are made 

 to excite the electro-magnets of twenty similar 

 machines to a degree sufficient to bring out 

 the maximum dynamic effect of each machine. 

 Mr. Wilde has ascertained that it is not neces- 

 sary to clutch the armatures together, for it is 

 a property of the current to make them re- 

 volve synchronously. 



In a paper read before the Manchester Lit- 

 erary and Philosophical Society, Mr. Wilde 

 mentioned the following as some of the results 

 obtained from the quantity armature of a 10- 

 inch machine. The dimensions of the coil of 

 this armature may be represented by a bar 

 of pure copper 67 feet long, and having a sec- 

 tional area of 1.6 square inches, so that the re- 

 sistance which this circuit presents to the pas- 

 sage of a current, when compared with that 

 of the liquids in a voltaic battery, is practi- 

 cally null. When the coil is in full action, it 

 will melt 15 inches of iron wire .035 inches in 

 diameter, or the same length of J-inch iron 

 rod with equal certainty ; and will electrolyze 

 acidulated water in at least 16 voltametres in 

 series; so that the resistance outside of the 

 circuit, whether estimated by the 15 inches of 



thin wire melted, or by the number of electro- 

 lyzing cells in series, is more than 100 times 

 greater than that of the coil in which the cur- 

 rent is generated. 



New Forms of Batteries. M. Ney has intro- 

 duced a battery composed of the ordinary cop- 

 per and zinc elements, but placed in different 

 solutions from those of the Daniell cell. An 

 amalgamated plate of zinc is put in a vessel 

 filled with a solution of chloride of ammonium ; 

 in this vessel is the porous cylinder containing 

 the copper plate, immersed in a solution of 

 carbonate of copper. It is claimed that this 

 battery can be kept a long time in active oper- 

 ation if the liquid ammonia is replenished, 

 which is easily done by dropping in solid chlo- 

 ride of ammonium. The natural carbonate of 

 copper can be used, and sand impregnated with 

 the ainmoniacal solution can be employed in- 

 stead of the solution itself. 



M. Rondet finds that his cyanide of potas- 

 sium battery possesses a magnetic force as com- 

 pared with a Bunsen of 81 to 93. He gives the 

 following comparisons between various forms 

 of battery: Bunsen, 933; chloride of potas- 

 sium and chloro-hydrate of ammonia, 601 ; 

 Mari6-Davy, 548 ; Daniell, 384. 



A battery invented by Abb6 Martin has 

 been found to have great electro-motive force 

 and peculiar constancy. The exterior jar, hav- 

 ing its lower part non-porous and well var- 

 nished, contains the liquid amalgam of zinc; 

 above this it is principally porous. Contact is 

 made with the zinc by a gutta-percha insulated 

 wire, whose extremity is bare ; this end im- 

 mediately on entering the liquid amalgam be- 

 comes amalgamated and establishes a thor- 

 oughly good contact. This interior cell con- 

 sists of a porous jar not resting on the amalgam, 

 but supported by the upper edge of the outer 

 vessel. Its porosity only extends to the lower 

 half, to prevent the exciting liquids mixing. 

 The negative element consists of a copper plate 

 or a plate of lead, carbon, platinum, or any 

 platinized metal, the exciting liquid depending 

 upon the metal, and being either sulphate of 

 copper, or salts of lead, mercury, silver, etc. The 

 exterior vessel is charged with dilute sulphuric 

 acid, and, by means of the porous portion of the 

 outer vessel, the sulphate of zinc is eliminated, 

 attaching itself to the side of the vessel. 



A New Frictional Machine. M. Ferdinand 

 Carr6 has recently constructed a new frictional 

 machine for the laboratory of the Sorbonne in 

 Paris. On the same axis are mounted two 

 disks of non-conducting materials. The first, 

 of gutta-percha, passes between two friction 

 cushions, and is provided with a brass conduc- 

 tor furnished with combs. The second disk is 

 larger than the first, but is not provided with 

 cushions only with a conductor and combs. 

 The action in the second is that of induction, 

 and in turning the handle powerful results are 

 obtained ; so much so, that, with disks from 

 14 in. to 19 in. in diameter, sparks are elicited 

 varying in length from 5 to 7 in. 



