Description of two new Voltaic Baiteries. 273 
ihe operator to experiment conveniently, the poles are 
brought to one end of the set of wheels, a brass bar almost 
as long as the axle is placed upon that side of the axle 
which is uppermost when the plates are immersed, and, 
with the exception of the terminating wheels, passes through 
all the rest near their centres. One end of this bar is con- 
nected by copper straps to the positive plate, and the other 
to acopper strap which, rising from the axle, passes through 
a slit in the front wheel ; itis then bent down, and fastened 
by a plate of brass, fig. 3, which is screwed firmly upon it. 
Another strap is soldered to the negative plate, passes 
through another slit, and is fastened in the same way, by a 
similar brass plate.* These brass plates, with the pincers 
for experiment, mounted, are represented ata. a. In fig. 
1, plate iti. the wheels are in the position which exhibits the 
plates out of the fluid. The pincers and brass plates are 
here shown to avoid the necessity of another plate, although 
not in their proper places. It is evident that, when the 
plates are immersed in the fluid of the cistern, the dotted 
lines b. b. mark the places which properly belong to them, 
and which must then be uppermost. When the operator 
has finished, and is about to turn the plates out of the fluid, 
he must first draw the pincers, &c. out of the brass plate. 
That this may be done almost instantaneously will be per- 
ceived by referring to fig. 3, which represents one of the 
brass plates with the pincer holder in its place—fig. 4 rep- 
resents one of the pincers. It is hardly necessary to state, 
that the instrument which I have now described is sufficient- 
ly powerful to melt the metals, ignite charcoal intensely, &c. 
In fact, with one part of nitric acid to ninety of water, I 
found it to be impossible to fix platina wire, one tenth of an 
inch thick, and several inches long, in the pincers, as it melt- 
ed instantly when in contact with the poles. In conformi- 
ty with common observation relative to large plates, it pro- 
duces neither shock nor decomposition. As in a cer- 
tain position, the uniting wire situated east and west, a 
magnetic needle suspended below and near the wire is re- 
versed, the north pole pointing directly to the south, its 
power in #his respect is probably sufficiently great to ac- 
complish all my purposes. I think it is not inferior, in re- 
* These two straps are well varnished. 
Vou. VIII.—No. 2. 35 
