O THE LATE MR. WILLIAM STURGEON ON 



which make the number of cases twenty, by allowing three 

 for the Favorite, In addition to these, there appears from 

 another report "prepared in compliance with a precept of the 

 House of Lords," dated June, 1849, to have been five cases 

 (within the same period) of lightning striking men-of-war 

 furnished with wire-rope conductors, which make a total of 

 twenty-five cases within a period of eight years. The Mindon 

 was struck twice, so that there are twenty-six lightning 

 strokes in the whole. 



63. In the absence of official returns to show the effects of 

 lightning, within the same period, on those ships of the royal 

 navy which have not been furnished with conductors, a com- 

 parison of the number of cases in which lightning has struck 

 men-of-war, with and without conductors, may be approxi- 

 mated by taking the mean of the latter class of cases for 

 eight years, out of all those that have occurred within the 

 twenty-four years previous to 1840, which, according to a 

 statement in the Nautical Magazine for May, 1844, amount 

 to fifty-two. This gives seventeen cases for each period of 

 eight years, which is about two-thirds only of the number of 

 cases that have occurred to those ships to which pointed con- 

 ductors are attached, a result by no means favourable to that 

 form of conductors being introduced into the navy. 



64. But if pointed conductors tend to favour the approach 

 of lightning towards those objects to which they are attached, 

 oblique discharges may find other channels of conduction, 

 amongst those objects over which they pass, the resistance 

 of which, at certain points of the transits, would be more 

 easily vanquished than that offered in a direct line to the 

 conductor itself. For, although a tall pointed conductor 

 might be the principal object in the locality for qualifying 

 the air so as to allow of a discharge taking place, the elec- 

 trical disturbance caused by the lightning subsequent to its 

 departure from the cloud, and the consequent electro-nega- 

 tions that it would enforce amongst objects within the range 



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