280 On Lightning Conductors to Powder Magazines. [No. 99. 



constructed, is by no means the infallible protection so generally 

 imagined. 



5. It is often no doubt easy to explain the occurrence of dis- 

 asters by lightning to buildings thus apparently protected, on 

 the ground of defective construction of the conductors, or of dis- 

 proportion between the number of conductors and the extent of 

 area to be guarded. By such considerations we may explain 

 the accident to Government house on the night of the 30th of 

 March 1838, and bearing these in mind, measures maybe adopt- 

 ed which in all probability will preserve such edifices from simi- 

 lar visitations. 



6. But it is a matter of greater difficulty to explain such 

 circumstances I am now about to adduce, in illustration of the 

 opinion expressed in paragraph 4. 



7- On an evening in May 183J, the house No. 2 in 

 Chowringhee, then occupied by Dr. Goodeve, and next door to 

 the house tenanted by Mr. Trower, was struck by lightning 

 and much damaged. 



Dr. Goodeve^s house had no conductor, Mr. Trowels had 

 one at the face adjoining Dr. Goodeve's, and only distant there- 

 from twenty feet. The conductor is well constructed. 



8. On the evening in question, during a violent storm from 

 the North-west, Dr. Goodeve was walking in the verandah (c) 

 when Mr. Trower's conductor and the corresponding angle of 

 Dr. Goodeve's house were struck by the same discharge, and 

 the lightning in Dr. Goodeve' s house followed the course of the 

 vertical window bolts represented by the dotted lines in the plan. 



9. This case seems to me completely to falsify Biot's opinion, 

 that within sixty feet interval between conductors no accident 

 can occur — and to shew that occasionally in tropical climates 

 there is such vast disproportion between the quantity or inten- 

 sity of the atmospheric electricity and the conducting capacity 

 of protectors, that the excess of the discharge must pass to adja- 

 cent bodies. 



10. In Chowringhee alone, in an area of one square mile, 

 there are over 300 lightning conductors of proper construction, 



