J. Nicklés on Different Applications of Magnetic Attraction. 343 
ever, succeeded in meeting the several points, and in making the 
resistance of the battery equal with that of the conducting wire, 
without too considerable a development in either the battery or 
elix. The wire was 4™m-5 jn section, with a total length of 
1036 meters ; each helix received 518, forming 216 turns. 
The battery consisted of 64 elements of Bunsen made with gas 
carbon ; the surface of the carbon in each element was 0™-911; 
that of the zinc immersed 0™-9148. These 64 elements were ar- 
ranged in 8 cases, having each compartments covered with gutta 
percha, as has been done by Prof. Page. he whole was placed 
behind the tender. In this position the battery was out of the 
way, and hardly seen in the train. 
This battery whether arranged for tension, or coupled for quan- 
tity in series of 32 elements with double surface, produces the 
same results whenever an equivalent direction is given to the cur- 
rent. ‘Thus when arranged for tension, a sitigle current is pro- 
duced ; and when for quantity, the current is diverted on arriving 
below the machine, so as to form a distinct current in each helix ; 
two conductors of copper wire answer in this experiment which 
is not quite delicate in other respects on account of the excessive 
conductibility of the materials which enter into the construction 
of alocomotive. ‘hese conductors were lodged in tubes of gutta 
percha, which were themselves covered with chamois leather, 
that was impregnated with varnish especially where these tubes 
are directly supported by iron. On reaching the point of junction 
the tender with the machine, these conductors are adapted to 
the conductors fixed to the locomotive, being bifurcated with them 
in a way to avoid rupture from the vibrations of the cars while in 
motion. From thence, they follow the left side of the locomo- 
of the wires proceeding from the helices. These last were sus- 
pended to the grease-boxes by means of strong clamps and a plate 
of iron. 
interrupted conductor which is in contact with one of the poles of 
the battery. | 
