104 
Balls.— Apparent Fallacies of 
RESISTANCE 
Suhickboard ceith. appendages ux dUaqrammahx pUn. 
Resistance RR Post Of free box and. cell 
(j R Unipluot gahjanometcr 
r L edits to suited 
'\ /N 
O = Mercury cups / \ / \ 
\/ V 
■ Bridge scvvtch 
r'r 2 Bridges (r'r' toE’E 1 , or r 2 r 2 toE^E 2 ) 
After testing resistance, the bridges are sunrn^ rourud t o positions b' b' or b 2 b 3 
Iruluxtorium PI Primary cod and celt 
51 SecoruUiy coll 
CC Commutator in primary circuit 
PKl Key breaking primary circuit ( and in its fall closing blaze circuit at KB) 
It Secondary leads to sunlch, through, raised teire arches 
Electrodes E Paired U' tubes 
A Tested object 
C Control 
b 1 b 7 Leads from electrodes to suited . Also acting as leads for secondary 
from suited to electrodes 
Blaze CjB Ayrton-Matder gaJvanomelcr 
bb leads from, switch to galvanometer 
KB K<y closing blaze circuit at a regular internal after break at KFl 
Note. After testing E'E 1 , li/t bridges from b 1 b 1 and close PKl before inserting bridges 
in b 2 b 2 for t he, testing of E 2 E 2 . The make-shock, is thus evaded 
