1840.] On Lightning Conductors to Powder Magazines, 285 



2. As in many instances it would, from the proximity of other 

 buildings, be impracticable to establish a chain of conductors at 

 a distance of twenty paces from a magazine, the Board would 

 be glad to learn whether, in your opinion, a series of conductors 

 at twenty paces distant from each other, but as near the build- 

 ing as ordinary conductors are commonly placed, and secured 

 by wooden brackets, as shewn on the sketch forwarded by the 

 Court of Directors, would add materially to the security of a 

 magazine. 



Fort William, I am, Sir, 



Military Board Office, XT v j« 



16th January, 1839, Your obedient servant, 



W. Debude, 

 Officiating Secretary Military Board. 



(No. 4.) 

 To Captain Debude, 



Officiating Secretary Military Board. 



Sir, — In reply to your letter of the 16th instant I have the 

 honor to state, that under such circumstances as you describe, 

 I would not recommend lightning conductors to be attached to 

 the buildings adjacent to magazines even in the numbers before 

 mentioned, as I feel convinced that placing one or more conduc- 

 tors in the immediate contiguity of the building increases all 

 the dangers attendant on the lateral discharge. Indeed I would 

 consider a magazine safer if unprovided with conductors al- 

 together, than with any number placed as you allude to. 



I believe we may certainly obviate all danger from direct 

 discharge by a multiplicity of connected conductors. I admit 

 too that the lateral discharge is not likely to occasion more 

 than a minute spark, such as would not harm a living animal, 

 or injure an edifice, but this spark, however insignificant, can 

 ignite gunpowder, and thus lead to as serious mischief as the 

 direct flash itself. I have the honor to be, Sir, 



Your most obedient servant, 



W. B. O'Shaughnessy, 



January 20th, 1839. 



