36 A. G. Beli—An Induction Balance 
I. Series of experiments with a ~ many! which had previously been in use 
a few min 
Hearing distance of leaden 
| bullet as observed by— 
| A. G. Bell. _ §. Tainter. 
cm. cm 
L cell”. oe eee ete eee ee 2°4 | 2°6 
2 2 cells in in ‘series Satins rs 3:3 3°5 
cells in series 3°] 4°] 
to origni- so oe ei gee eed 37 40 
5 cells in conlrenis Sserien SMe Ae ee 4°0 4°] 
6 cells in =e 4°3 4°4 
6 cells in mnitiale SEO eels: 2°6 2°9 
0o 
6 cells in two series of 3 each ___.__-- — oo | — 3°8 37 
oo 
__|oeoo| _ 40 
pore yews series of 2 each. _--- -- > > een} |: 4:3 : : 
Il. Series of experiments with a Leclanché battery of twenty cells which had been set 
up for about one month. It had been kept normally upon open. cireuit, and had 
only been occasi ocometly used. 
Hearing distance. 
20 cells in series 3-Zem 
20 cells in 10 series of 2 each 36? 
20 cells in 5 series of 4 each 4°]e™ 
20 cells in 2 series of 10 each_.__- 3°30m 
Although the battery appeared to be in good condition, a 
close inspection showed that the connections were dirty, an 
that one of the zinc wires was half broken through. 
he defective cell was now removed from the circuit, and 
the connections of all the other cells cleaned and tightened. 
Ill. The following experiments were then made with the Leclanché cells united in 
series : 
No. ofcelis. Hearing distance. No. of cells. Hearing distance. 
cm. em. 
hi 2°7 11 3-8* 
2 2°8 12 4°2 
3 3°70 13 42 
4 3°3 14 4°2 
5 3° 15 43 
6 a5 16 4°2 
7 3°6 a 4°2 
8 3°38 18 4°2 
9 4-6 19 4°2 
10 3°8* 
These results are ain represented in fig. 12. 
It will be observed that the hearing distance was carried 
nearly one-third as far see as at first, simply by increasing 
the number of cells employed without any other change in the 
* Balance not quite perfect. 
