PROTECTION AGAINST LIGHTNING. 817 



The conductor wliich was attached to the spire was not adequate and 

 competent for the protective work which it was intended to perform. 

 It had been put up sixteen years ago, when a new spire was erected in 

 the place of the old one, which fell in consequence of having been add- 

 ed as an after-thought to a tower that had not been prepared to bear 

 its weight, and was of a form which is, happily, now obsolete. It 

 originally consisted of twelve No. 15 gauge * copper wires aiTanged 

 in a double series, side by side, and held together by a double strand 

 of zinc and copper wire crossing them transversely, and acting as a 

 kind of weft to the longitudinal copper warp. The conductor was 

 thus a sort of ribbon of copper wire, with transverse binding-threads 

 of zinc. The weight of the metal in this compound conductor was 

 ten and a quarter ounces per yard, instead of being thirty-six ounces 

 per yard, as it ought to have been at the very least if it had fulfilled 

 the conditions that are now required for such a task as it had been 

 required to perform. But, besides this, in consequence of having been 

 exposed for sixteen years in its sub-littoral situation to the blasts of 

 the moist sea-wind, the copper wires were in many places eaten into 

 by corrosive action where the zinc wire of the woof crossed them, so 

 as to reduce to some considerable extent their original conducting ca- 

 pacity. The conductor was so fixed that it descended from the sum- 

 mit of the spire along the slope, and along the face of the tower, then 

 crossed the lead flashing of the roof, passed down the main wall of the 

 building near the intersection of one of the transepts with the nave, 

 and was finally plunged into a well dug into the grave-yard about 

 twenty feet from the place where it reached the ground. At the time 

 of the storm a flash of light was seen to pass along the upper part of 

 the track of the conductor, and this flash was accompanied by an 

 instantaneous crash of thunder, that awoke most of the slumbering 

 inhabitants of the close. The destruction of the conductor, however, 

 was not discovered until the second morning after the storm, when 

 some shattered fragment was observed projecting from the tower. It 

 was then found that about forty feet of the conductor at the top of 

 the spire still remained uninjured in its place, but that for the next 

 one hundred feet below this the woven metallic band had been scat- 

 tered into a shower of short fragments of copper wire, which were 

 strewed thickly upon the roof of the tower and of the lower building. 

 These fragments were three quarters of an inch long, corresponded in 

 length with the materials of the transverse crossings of the zinc wire, 

 and bore unmistakable indications of galvanic corrosion upon their 

 ends. The lower portion of the conductor was uninjured, but one of 

 the iron rain-pipes, which descended from the roof of the transept a 

 few feet away, had been shattered by the discharge. It was therefore 

 manifest that from the leaden covering of the roof downward the 

 incompetent conductor had been assisted in its work by the roof and 



* That is, of one sixteenth of an inch in diameter. 



VOL. XXT. — 52 



