and the effects of lightning on H.M.S, Rodney^ ^c. 127 
action ; thus we find the points of ingress and egress of an 
artificial charge, when caused to fall on a slip of gold leaf or 
other matter, are always those in which the most powerful 
effect arises ; and when we desire to fire inflammable matter 
by electricity we place it directly between detached metallic 
points. 
21. The circumstance of the lightning striking over portions 
of the wet mast without damage, is precisely the same effect as 
observed in certain cases of artificial electrical discharges.Thus 
a very slight film of moisture will allow a jar intensely charged 
to discharge a luminous ball over a long strip of glass. Dr, 
Franklin found he could destroy a dry rat by an electrical 
shock when he failed to hurt a wet one. If we continue to 
follow the discharge we find similar expansive and destructive 
effects; such as the bursting of the hoops on the mast, &c., 
&c., which will sometimes occur and sometimes not. 
22. There is really nothing in all this to call for especial 
remark, except we may observe, as shown by the experiments 
already described, that if a good capacious conductor had been 
incorporated with the mast from the truck to the metallic masses 
in the hull and to the sea, then these expajisive and destructive 
effects could not possibly have occurred; since the interrupted 
circuit would have been avoided, and the intense electrical action 
have vanished, or nearly so, at the mast-head, for it would 
have no longer been driven to force its way in a dense explo- 
sive form to the hull and sea; of this we have the most com- 
plete evidence from, experience, particularly in the cases of 
the ships struck by lightning having such conductors as those 
just alluded to, curiously enough quoted by Mr. Sturgeon as 
evidence to the contrary. It seems a strange way of disproving 
a fact to quote those who, having been eye witnesses, insist 
upon its truth. That the electric matter finally distributed 
itself upon the hull as ^ell as on the sea, is evident from the 
circumstance of the casing of Flearle’s pump at t, w’hich 
led through the side under water being shivered ; from the 
vivid electrical sparks below, and from the usual smell of sul- 
phur in the well, and appearance of smoke in the orlop-deck, 
23. The interrupted circuit therefore to be traced here, is 
first from the vase-spindle to the copper funnel of top-gallant 
rigging ; 2nd, from this to the conducting bodies at the heel 
of the top-gallant mast; 3rd, thence to the metallic masses 
about the parrel of topsail-yard; 4th, between this and the 
metallic bodies about the head of lower mast ; 5th, from this 
over the detached metallic bodies on lower mast ; finally, from 
lower mast to the hull and sea. The effect of this shock of light- 
ning appears to have been somewhat palliated by heavy rain. 
