258 CC. G. Page on the Economical Constant Battery. 
is an interesting fact, that if the box is varnished or painted 
outside before the varnish is applied inside, it cannot easily be 
‘ 
box of wood prepared in the same manner. G is the nega- 
tive or condueting plate of the battery, made of wire gauze or a 
perforated plate. In my first batteries these plates were made 
of copper, but after the introduction of Smee’s battery, I felt 
satisfied that with Smee’s improvement, this form of battery 
the Coast Survey, who has great skill in the management 
batteries and the art of electrotyping, informs me that it is pet 
fectly practicable. It is worthy of note here, that Mr, Mathiot 
has adopted this battery in some of his experiments entirely from 
1s own suggestions, and it is gratifying to me to learn that he 
thinks highly of it for many purposes. The kind used by Mr. 
Mathiot is that shewn in fig. 1, except that his vessels are of 
glass instead of wood, and he had made no provision for leading 
off or using the hydrogen. 
H is the amalgam of zine. 
D its connexion with the wire from N. 
P, N, the poles of the battery. 
