1840.] On Lightning Conductors to Powder Magazines, 309 



" There can be no doubt that a conductor in the moment of 

 a discharge of electricity passing through it, influences in a 

 degree all good conducting substances in its immediate vicinity, 

 by induction, but no discharge will take place from it to any 

 neighbouring body, unless it be insufficient itself to con- 

 duct the whole of the charge." * * * 



45. To this I have only to add, that since my first re- 

 port (Dec. 1838), in a paper published by Mr. Sturgeon in 

 the Annals of Electricity for October 1839, precisely the same 

 ideas as those I entertain are fully and ably advanced. Mr. 

 Martyn Roberts, a well known electrician, advocates the same 

 views — such also were the opinions of my admired and esteem- 

 ed friend James Prinsep, whose name alone is full proof, to the y f^3f\ 

 Indian community at least, of the sterling value of the conclu- v 

 sions he arrived at. 



46. From the consideration of all these facts and reasons, 

 I think myself justified fully in adhering to the opinions ex- 

 pressed in my first report. I do not, and never did, deny the 

 protecting power of well constructed conductors erected in a 

 given number. I stated distinctly all the circumstances from 

 which danger might result, and how I conceived these might 

 best be avoided. I freely admit copper to be superior to iron, 

 but I wished to avoid expense in introducing the system I pro- 

 posed. On that system I conceive all danger would be obvi- 

 ated, while in the method proposed in the letter from the 

 Honorable Court at least two highly probable causes of 

 accident remain in full operation. 



47. Having obtained through your Board the sanction of 

 Government to the publication of the papers by Messrs. 

 Faraday and Daniell, I will take care that the views therein 

 contained shall be generally made known. In an early number 

 of the Journal of the Asiatic Society, I propose further to print 

 an abstract translation of M. Arago's remarkable Essay " Sur 

 le Tonnerre" which I saw for the first time when it was sent 

 to your Board, along with Messrs. Faraday and Daniell's 

 papers. The interesting facts with which M. Arago's me- 

 moir abounds, will doubtless lead many competent observers 

 to study the phenomena and effects of lightning on the grand 

 scale in which these may be witnessed in India. A multitude 



