71 



Even in those cases, where lightning conductors have not 

 extended continuously through the whole height of a build- 

 ing, or where the lower extremity of the conductor has, 

 from any cause, terminated abruptly at the base of the 

 building, the severity of the stroke has been greatly miti- 

 gated, the damage being limited, in many case, to the 

 loosening of a few stones or bricks. 



The ever extending introduction of gas and water pipes 

 into the interior of buildings armed with lightning con- 

 ductors has, however, greatly altered the character of the 

 protection which they formerly afforded, and the conviction 

 has been long forced upon me that, while buildings so armed 

 are effectually protected from injury of the mechanical kind, 

 they are more subject to damage by fire. 



The proximity of lightning conductors to gas and water 

 mains, as an element of danger, has not yet, so far as I 

 know, engaged the attention of electricians, and it was first 

 brought under my notice at Oldham in 1861, by witnessing 

 the eflects of a lightning discharge from the end of a length 

 of iron wire rope, which had been fixed near to the top of a 

 tall factory chimney, for the purpose of supporting a long- 

 length pf telegraph wire. The chimney was provided with 

 a copper lightning conductor terminating in the ground in 

 the usual manner. In close proximity to the conductor, 

 and parallel with it, the wire rope descended, from near the 

 top of the chimney, for a distance of 100 feet, and was 

 finally secured to an iron bolt inserted in the chimney 

 about 10 feet from the ground. During a thunderstorm 

 which occurred soon after the telegraph wire was fixed, the 

 lightning descended the wire rope, and instead of discharging 

 itself upon the neighbouring lightning conductor, darted 



