103 



PREVENTION OF DAMAGE BY LIGHTNING. 



V. 



On the Prevention of Damage by Lightning. In a second 

 Letter from Mr. Benjamin Cook. 



Conductors of 

 Jightnmg. 



Occasional 

 failure no 

 proof of their 

 inuUiity. 



Probable 

 causes of 



er even mis- 

 chti f i'roru 

 them. 



To Mr. NICHOLSON. 



DEAR SIR, 



I 



N a former paper, which you inserted in your very valu- 

 able Journal*, ou the advantage and security that I 

 supposed the nation would enjoy, if electric rods were 

 placed at certain distances on the most elevated parts of the 

 country, or if attached to the highest buildings at different 

 places, so that the electric fluid might be carried off" by the 

 rods, as the clouds charged with the fluid passed over them ; 

 by your remark at the close of that pa[)er, it did not seem 

 to strike you, as promising that advantage and security it 

 did liie, and you named an instance, where the rods had 

 failed : Bat il" one instance, or two, have happened, where 

 the electric rods do not appear to have had any influence on 

 the electric fluid, so as to carry it off without injuring the 

 buildings, this is no proof of their inutility. We ought, 

 before we pass judgment upon them, to have known the 

 state of the rods, and their elevation. It is very probable, 

 that these rods had been up for many years, and nearly 

 destroyed by rust ; and perhaps in some parts the nature of 

 the iron might have been completely changed or destroyed, 

 and nothing left but rust ; nay in some places, even the 

 rods might have been divided, or nearly so, by the rust ; so 

 that a weak discharge of the electric fire would easily melt 

 ■what was left; or they might have been carried in such 

 directions across, or down the sides of the building, as to 

 pass by substances possessing greater power to carry off the 

 fluid, than such rusty decayed conductors; and thus the 

 lightning might have been by their means conducted so as 

 to cause the very ruin, they were intended to prevent. — 

 Besides, the points of the conductors might have been 

 placed very low, so that clouds overcharged with the electric 



• Vol. XXIX, p. 305. 



fiuid 



