and, the effects of lightning on H,M,S. Rodney^ ^c. 1 17 
phaenomenon in electricity, termed by Cavallo, Priestley, and 
others the lateral explosion, and showed that it did not apply 
to the state of a metallic rod in the act of transmitting a va- 
nishing electrical accumulation between two opposed electri- 
fied surfaces, as insisted on by Mr. Sturgeon in a recent num- 
ber of his Annals of Electricity. I will now proceed to ex- 
amine the general character and effect of ordinary electrical 
discharges, whether produced on the great scale of nature, 
or artificially, with a view of further showing, that such lateral 
explosions do not occur at the instant of the passing of a 
shock of lightning through a metallic conductor, as alsc^with 
a view of meeting certain other objections which have been ad- 
vanced at different times to the use of lightning rods in ships. 
2. 1 should not have felt myself called upon to notice fur- 
ther Mr. Sturgeon’s memoir, did I not consider the state- 
ments it contains, although superficial and inconclusive, likely 
to mislead the public upon many important points connected 
with the effectual protection of shipping against the destructive 
effects of lightning, and convey false views of the nature of 
electrical action. Under these impressions I have little hesi- 
tation in noticing what he has advanced under the following 
heads : — 
1st. Examination of the observed effects produced on 
shipping by lightning. 
2nd. A comparison of the observed effects of lightning 
and the probable effects which lightning would pro- 
duce by the application of Mr. Harris’s conductors to 
shipping. 
3. The first contains an excellent, and I have no doubt, an 
accurate statement, by an intelligent officer of the Rodney, of 
the destructive effects of lightning lately experienced in that 
ship, together with notices of two cases in which ships fitted 
wdth my conductors were struck by lightning without any 
attendant ill consequence. In the second, it is the author’s 
object to prove, from the effects of lightning in the Rodney, 
that my system is inadmissible; since the discharge of light- 
ning, he observes, which struck the Rodney, would have 
been powerful enough to have rendered even the thickest 
part of Mr. Harris’s conductors sufficiently hot to ignite gun- 
powder.” 
Considering the boldness of this assertion, and the high 
pretension of the memoir, w^e should expect, on examining 
the author’s researches, to find him in possession of a copious 
induction of facts from well-authenticated cases of damage by 
lightning on ship-board, illustrating clearly the views he so 
strenuously insists on, — cases in which continuous or other 
