120 Mr. Snow Harris on Lightning Conductors 
ting in a point, and equalizing with inconceivable rapidity the 
disturbed electrical state of the sea and clouds. 
8. The manifest deficiency of sound practical information in 
Mr. Sturgeon’s memoir, imposes upon me the necessity of ad- 
verting to the general character and operation of common 
electrical discharges, whether produced by artificial means or 
on the great scale of nature. In doing this I have no desire 
to excuse myself, in case I should not have written clearly and 
explicitly on the subject, since in no department of physics is 
the field of observation so fertile, and the path of experiment 
so sure and easy. We have before us the experience of nearly 
a century, during which time lightning-rods have been em- 
ployed ; a great number of instances have occurred of shocks 
of lightning falling on ships under a variety of different cir- 
cumstances, in some cases where lightning conductors have 
been present, in others where absent ; in many instances where 
ships have been near each other and exposed to the same 
storm, some having conductors, others not. The general laws 
of the discharge are traceable in them all, and the effects on 
metallic bodies distinctly shown. On the other hand, we can 
on a minor scale, imitate successfully the great operations .of 
nature, and examine experimentally every possible contin- 
gency attendant on the operation of a shock of lightning in a 
ship. It is our own fault, therefore, if we do not treat the 
subject scientifically, and arrive at complete practical solutions 
of such questions as these : Is a lightning conductor desirable 
in a ship ? Will it cause by attraction a shock of lightning to 
fall on a ship when otherwise such would not take place ? If 
so, can it cause damage by its inability to get rid of the light- 
ning which falls on it? What is the best form and dimensions 
of a lightning conductor for a ship ? What is the greatest 
probable force of lightning to which it may become exposed ? 
Is it liable to cause damage by any lateral operation of the 
charge passing through it ? I say, if such questions as these 
cannot now be reasonably determined they probably never 
can ; and, therefore, any one who writes or reasons obscurely 
about them, and without due regard to a good induction- of 
facts, can have no claim to be considered as a sound reasoner 
in experimental science; for, as beautifully observed by 
Lord Bacon, Man, who is the servant of nature, can act and 
understand no further than he has, either in operation or in 
contemplation, observed of the method and order of nature.” 
Under these impressions I proceed to examine the general 
character and effects of electrical discharges as exhibited arti- 
ficially, and on the great scale of nature. 
9. Although some theoretical differences may have arisen 
