1840.] On Lightning Conductors to Powder Magazines. 295 



recollect that his opinions, as well as mine, have to bear the 

 scrutiny of individuals who are not very likely to be influenced 

 by the mere reputation of any of the parties concerned. 



5. The question before the Board, is this exclusively, " Are 

 we to attach lightning rods to powder magazines : and if so, 

 how are we to place them, so as to ensure the maximum of 

 safety from every accident ?" To this question and its bearings, 

 we must limit this discussion. It is altogether a different 

 matter from that with which Mr. Daniell has mixed it up, 

 namely, the attaching of conductors to private dwellings, or 

 ordinary buildings. All the circumstances differ so widely, 

 that many of the most important of the facts and arguments 

 which bear on one, are altogether inapplicable to the other. 



6. The necessity for attaching lightning rods to powder 

 magazines in tropical regions, visited by frequent and violent 

 thunder storms, might at first sight appear so obvious, as to 

 need no further consideration. The document (A) how- 

 ever shews, that of all the magazines in the territories of the 

 Honorable East India Company, during a period of forty years, 

 only one has been struck by lightning, namely that at Dum- 

 Dum, on the 1st of June 1836. It will be seen, as we proceed, 

 that the term " magazine" was scarcely applicable to the build- 

 ing then destroyed. 



7. I stated in my first report on this subject, that I consi- 

 dered a powder magazine when properly constructed, arched 

 and rounded in its outlines, of low elevation, and free from 

 metallic masses in its walls and roof, to be as little exposed to 

 accident as an equal area of soil or terrace, the chances of 

 which being struck by lightning are so infinitely small, as 

 scarcely to deserve serious consideration. The Dum-Dum 

 explosion took place in a common building of square form, 

 formerly a godown. It was not a magazine, but a mere store- 

 room for the powder used for the laboratory. It stood in the 

 corner of a yard crowded with guns, gun carriages, heavy metal 

 tools, shells, and other powerful conductors of electricity. It 



