272 Descripiion of two new Voltaic Batteries. 
the hands of other experimentalists. My motive for ad- 
dressing you, now is merely to describe the plan which J 
have adopted, as I have found it to be eminently useful in 
relation to the objects to which I have alluded. The re- 
sult of a series of experiments in which I am engaged shall 
be communicated to you for a future number. 
Eight wheels (see plate III.) made of strong pieces of 
plank, screwed to each other transversely, four feet in di- 
ameter and one inch and five-eighths in thickness, are pla- 
ced upon an axle six inches in diameter, and five feet nine 
inches in length, having brass gudgeons one inch and a half 
thick, at each extremity. These wheels are arranged in 
pairs, each carrying thirty semicircular plates of copper 
and zinc, thirty-nine inches in diameter. In order to pre- 
pare them for the reception of the plates, they are placed 
about ten inches from each other and retained in their po- 
sitions by eight strong pieces of ash, morticed and screwed 
into their edges, by which they are firmly connected. Five 
of these cross pieces are indented by a saw that they may 
receive the edges of the plates, and keep them at proper 
distances. Each pair of wheels, charged with the plates, 
is separated about two inches from the next, as they are 
all intended to revolve in a cistern with divisions. ‘The 
plates are counterbalanced by pieces of lead, painted and 
varnished, attached to the cross pieces on the opposite 
side of the wheel. The dotted lines d. d. indicate the sit- 
uation of these counter-weights. The cistern is supported 
by strong pillars of glass—is six feet long, four feet four inch- 
es wide, and two feet three inches deep. {tis divided inte 
four cells, by three pieces of one and a quarter inch plank, 
morticed into the bottom and sides, and rising to within 
four inches of the top of the cistern, for the purpose of per- 
mitting the axle to turn freely. The whole is well painted 
with white lead, and covered with several coats of copa! 
varnish. The plates are arranged as in fig. 2, and the ter- 
minating plates of each division are connected by a strap of 
copper, four taches broad, soldered to their edges. This 
strap rises from one plate (for example) until it touches the 
axle, then passes through the wheel in contact with the axle, 
until it passes through the opposite wheel; it then dips 
down to join the edge of the first plate of the next division, 
which is in a different electrical state. In order to enable 
