102 
Annual Report of the 
stroke. This occurs when, by the inductive action of one or more 
clouds upon points widely separated, the electricities having ac¬ 
cumulated at these points, a discharge takes place at one point and 
the equilibrium is suddenly restored at the other. Life is some¬ 
times destroyed in this way. 
It should be observed that animal life may be destroyed by the 
simple transmission of a large quantity of electricity through the 
living body, though a good conductor. This is probably owing to 
the repulsive energy imparted to the particles of the blood and 
other parts of the body. In the same way living trees are riven by 
the lightning-stroke. 
LIGHTNING-RODS. 
How then do lightning-rods afford protection from these destruc¬ 
tive effects ? The answer to this question, after what has been said, 
will be easily understood. Lightning-rods being prominent and 
pointed conductors, and supposed to be intimately connected with 
the moist earth, present the conditions required for the most per¬ 
fect induction. The inductive action of the cloud will therefore 
take place mainly in the rod rather than in the surrounding objects. 
Hence the electricity which is drawn from the earth to neutralize 
the redundant electricity of the cloud, must pass from the rod, in¬ 
stead of the building on which it is placed. So in case of the 
return stroke, the equilibrium is restored through the rod. To be 
more specific, a lightning conductor affords protection in two ways: 
first by silently drawing off the free electricity from the charged 
cloud, and thus, for the time, disarming it of its fury. This it does 
by the action of the point as already explained. A rod properly 
constructed, will in nearly all cases, by thus neutralizing the 
electricity of the cloud, prevent an explosive discharge. Lightning- 
very rarely strikes in cities or villages, because the many pointed 
• rods and spires gradually and silently conduct off the redundant 
electricity from the thunder clouds before they come within 
striking distance. Clouds watched from an eminence may be 
seen to descend as they pass over a village, and then rise again, 
showing the action of the pointed objects. But secondly, in case of 
an explosive discharge, the electric fluid will pass harmless through 
the rod only, as before shown, the charge being thus drawn away 
from the building itself. There is abundant proof that lightning 
