SOURCES OR ELECTRICITY. 
205 
Leclanche has lately modified the form of his battery. He 
now compresses the mixture of peroxide of manganese and 
coke by means of a hydraulic press ; and with a little shellac 
he is able to consolidate the whole together with the con¬ 
ducting plate of carbon into a cylindrical form. In this way 
the porous vessel is dispensed with. The zinc, of the same 
shape as before, is separated from the carbon cylinder by pieces 
of wood, and is kept in its place by India-rubber rings 
(fig. 144). 
r 
Fig. 143. 
Fig. 1-14. 
This battery is the cleanest and most convenient with which 
we are acquainted. It can remain a very long time without 
attention, if it be used for the purposes for which it is 
intended. The great railway companies in France employ 
scarcely any other battery, and there are stations where it is 
still working perfectly after having been nine years in use. 
A simple and convenient form of Daniell’s battery which is 
very commonly used in England for telegraphic purposes may 
here be described. It consists of a long trough or box, 
for it is generally provided with a lid, and a quite 
usual size for it is 2 feet in length, 6 inches wide, and 
inches deep. This is divided by transverse partitions of 
