Whether Lightning Rods attract Lightning. 593 



We shall now leave the theoretical discussion of this question, 

 and direct attention to the facts themselves, and examine how far 

 the evidence deducible from such facts is conclusive upon this im- 

 portant point. 



During the thunderstorm which spread over the neighbour- 

 hood of Plymouth, in May, 1841, the electrical discharge struck 

 one of the high chimneys at the Victualling- Yard, as already 

 mentioned (94) ; it fell also on the topmast of the sheer-hulk off 

 the Dock- yard, about a mile and a half distant. Now the circum- 

 stances attendant on these discharges of lightning bear directly 

 on the question before us. The chimney at the Victualling- Yard 

 is a round column of granite, about one hundred and twenty feet 

 high, attached to the bakehouse ; it has not a particle of metal in 

 its construction, nor has it any projecting point. It stands at a dis- 

 tance of about one hundred yards from a clock-tower in the same 

 yard ; which on the contrary, has not only a metal vane, and cross- 

 pieces of metal, indicating the four cardinal points, but its dome is 

 covered with copper, and there is a large conductor continued part- 

 ly within and partly without the tower, from the dome to the 

 ground. In the sheer-hulk a very small metallic wire was led 

 along the pole topmast, and connected with large metallic chains 

 attached to the mast and sheers: the height of this pole was 

 comparatively low, and it was completely overtopped by the neigh- 

 bouring spars of the line-of-battle ship Cornwaltis, fully rigged, 

 and fitted with conductors on each of her masts. Now when the 

 disruptive discharges took place, they fell on the granite tower, 

 which had not a single metallic substance in its construction, and 

 on the low flag-staff pole of the sheer-hulk's mast, notwithstanding 

 that the clock-tower near the chimney offered every possible " in- 

 vitation" to the discharge, and the great altitude of the line of battle 

 ship's spars were in the most favourable position for " attracting" 

 the electrical explosion. The chimney was rent for sixty feet ; the 

 flag-staff of the hulk's mast was slightly injured, and the small wire 

 broken and fused ; the lower mast and chains were uninjured. 



On the 25th of March, 1840, Her Majesty's ships Powerful and 

 Asia, each of eighty-four guns, were at anchor within a short dis- 

 tance of each other in Vourla Bay, in the Mediterranean. The 



