594 Whether Lightning Rods attract Lightning. 



Asia had the fixed pointed conductors already described (84) at- 

 tached to each of her masts ; the Powerful was unprovided with 

 any lightning conductor whatever. Under these conditions they 

 were both exposed to a severe thunderstorm. A discharge of 

 lightning fell on the Powerful, the ship without conductors, and 

 shivered some of her spars ; whilst the Asia, where every supposed 

 " invitation" to the discharge was most prominent, experienced no 

 ill effect. 



If no other cases were on record, these alone, would be suffici- 

 ent to dispel all apprehensions of a metallic conductor " attracting 

 or inviting" lightning. A great number of instances, however, 

 equally clear and satisfactory, exist ; from these we have selected 

 the following :— . 



Amongst some interesting remarks on the effects of lightning, by 

 Professor Winthrop, communicated by Dr. Franklin to Mr. Henley, 

 it is stated, that a tree, which stood at the distance of fifty-two feet 

 only from a pointed conductor attached to a house, was struck by 

 lightning and shivered, while the conductor and house escaped*,-— 

 that is to say, the lightning fell on a body, which, according to the 

 prevalent notion, had little or no attraction for it, and held out no 

 11 invitation," in preference to one which did, — a fact totally at vari- 

 ance with the whole assumption. 



We have already adverted to the case of the Southampton (46), 

 in which a heavy electrical discharge fell upon the sea close to the 

 ship, during a thunderstorm on the east coast of Africa. But what 

 makes this case especially applicable to the question now under 

 consideration, is the circumstance, that all her masts were fitted 

 with fixed lightning conductors, which terminated in copper spikes. 

 The storm was awful, and is stated by Mr. Martin, the master, to 

 have lasted from ten p.m. to two a.m. " The night was pitchy 

 dark, from the density of the surrounding clouds ; the roar of the 

 thunder was incessant, and the flashes of lightning frequently so 

 vivid as to affect the sight for some minutes," yet no ill effect was 

 experienced ; the electrical discharge was not drawn down in an 

 explosive form exclusively upon the conductors, although it actually 

 fell with violence upon the sea close to the vessel. 

 * Phil. Trans, vol. lxiv., p. 152. 



