108 Steam Boats protected from the Effects of Lightning. 
the iron of the boat, the electricity will always take the steam in 
preference to striking any part of the boat; and this it will do in so 
diffused a manner, as never to be perceived or felt. If a boat is 
ever struck, we presume it will occur while she is lying cool at the 
wharf, and beyond the influence of higher objects; but in no in- 
stance probably will it ever happen while she is discharging steam. 
Houses could be protected in a similar manner, provided a steam 
tube should be made to pass from a boiler at the ground, to the top 
of the chimney ; but as Franklin rods are equally good protectors, 
and much cheaper, they are to be preferred. 
Remarks.—It will be remembered that, some years since, proba- 
bly as many as ten, (for I have no document at hand to refer to, for 
particulars) the boiler of a steam boat, I believe in motion, explo- 
ded in the harbor of Charleston, South Carolina, in consequence of 
astroke of lightning. The boat was under the general superintend- 
ance of the late Mr. Samuel Howard,* of Savannah, who was on 
board ; and in a conversation with me on the subject, he attributed 
the explosion to the sudden expansion of the steam by the lightning. 
Perhaps this fact does not militate against the views of Dr. Jones, 
for there may be discharges of atmospherical electricity too powerful 
to be quietly disposed of by any artificial conductor ; that is, the 
amount of the electric fluid may be greater in a given case, than 
steam or metal can transmit without accumulation of heat, and with- 
out violence. The heat produced by electric discharges, although 
transient, is often very great, and if in the case above referred to, the 
mere expansion of the steam by the lightning, should not be sup- 
posed sufficient to account for the effect, is it not possible that there 
might have been a great addition to the quantity of steam, by the elec- 
tric heat transmitted through the metal of the boiler to the water, - 
and through the water itself, which is an imperfect conductor ? 
There can be no doubt that a steam boat is less liable to be. torn 
by lightning, than a vessel of the common construction ; for, not to 
mention the steam, her iron chimney and working piston, and in short 
all the masses of iron present a large conducting surface for the 
lightning, and the connexion is finished by actual contact of the metal 
with the great flood of waters beneath. A steam boat is somewhat 
in the condition that a ship would be, whose masts were all of iron, 
seo idles. teem ee a 
ee i. 4 phil hhical-mind. 
