Lightning Conductors in Ships. 357 
18. The manner in which conductors here proposed are applied 
to the mast, gives the form of the whole,—that of a flattened, conical 
surface,—wide at the base, and diminishing gradually toa point. It 
has been stated by one of the most eminent of the French philoso- 
phers, that this form is the best possible for a lightning-rod. 
19. The objections made to fixing lightning-conductors in ships, 
are for the most part such as have been urged against lightning-rods 
generally ; and are principally as follows :—It is said, that by fixing 
continuous lines of metal in the masts, we invite an electrical dis- 
charge from the atmosphere, and that by means of an attractive 
power, which, it is assumed, the metal is possessed of, the explosion 
is drawn exclusively upon the vessel; that, inasmuch as we can never 
come to know the absolute quantity of electric matter which may be 
discharged from a thunder-cloud, it is possible that the transmitting 
power of any conductors we can apply, may be inadequate to the 
end in view, so that they may possibly become fused ; and hence it 
isinferred, that much damage may be the consequence :—That in 
fixing lightning-conductors in the masts, we can only have surface ; 
whereas, the properties of a conductor depend on the mass, and not 
on the surface of the metal: hence the metallic surface is calculated 
to do considerable mischief, by conducting the lightning into the body 
of the vessel. Such are the principal objections to this application, 
and which, it is hoped, are fairly stated. They are highly deserving 
serious consideration, . but they will be found, on examination, to be 
inconsistent with experience, and with the known laws of electrical 
action. We shall, however, by a candid inquiry, give these objec- 
tions all the attention which their connection with so important a ques- 
tion demands. 
20. The notion that a lightning-rod is a positive evil, will be found 
to have arisen out of the fact already mentioned (8), namely, that 
lightning invariably passes through the line or lines of least resistance 
tween the points of action; hence it seizes on all those substances 
Which oppose the least resistance to its passage ; metallic vanes, vane 
spindles, iron bars, knives, and pointed metallic bodies, generally, 
Will therefore be very commonly found in the course of the explo- 
Sion; and from this circumstance, they have been considered to ex- 
ert an attractive force upon the matter of lightning, so as to draw it 
aside from its destined course, to the destruction of the substances in 
®onnection with them. 
