134 PHILOSOPHICAL TRANSACTIONS. [aNNO I764. 



and lead employed in this steeple, in order to strengthen and preserve it, did 

 almost occasion its destruction : though after it was struck by the lightning, 

 had it not been for these materials keeping the remaining parts together, a great 

 part of the steeple must have fallen. 



The operation and progress of the lightning, in the obelisk and upper parts of 

 the steeple, deserve more particular attention. To form a more perfect idea of 

 these, the following measures will in some degree contribute. 



Feet Inches. 



The height of the octagonal obelisk 32 3 



Length of the iron spindle 19 • • • • 9 



Thickness of the spindle, where inserted into the stone 2 square 



Its length inserted into the stone 9 10 



From the bottom of the spindle to the first cramped joints . . 5 10 



Three courses of stones without cramps 5 .... 7 



From the bottom of the spindle to the first concealed chain. . II .... 5 

 From the first concealed chain one foot above the base of the 



obelisk to the first cross chain 2 .... 



From the first cross chain to the 2d, placed in the dome. ... 8 10 



The vane, the cross above it, the ball and its socket, which covered so much 

 of the spindle as arose above the stone, to near 10 feet of its length, were of 

 copper gilt. This length of the spindle was cylindrical, but the other part was 

 made square, where it began to be inserted into the stone. To fasten this 

 spindle more securely in the courses of stone, melted lead had been poured. 

 This lead, in the two lower courses of stone through which the spindle had 

 passed, not only filled all the space left between the spindle and the stones ; but 

 had, as it were, ramified itself not only between the joints of the stones, but 

 had insinuated itself in its melted state into all their small clefts and interstices. 

 The spindle terminated in one stone, which occupied the whole area of the 

 obelisk, and was 3 feet and near 2 inches in diameter, and one foot in thickness. 

 Into this stone the spindle was inserted 5 inches of its depth, and fastened by 

 melted lead. Under this stone the obelisk was hollow ; but above it was solid, 

 excepting the space left for the spindle. 



On examining these several particulars, no injury had been done by the light- 

 ning to the vane, its cross, copper ball, or spindle. Of the 7 courses of stone 

 at the upper part of the obelisk, and which were above the whole stone into 

 which the spindle was inserted, the 5 upper courses, though connected together 

 at top and bottom with iron collars soldered with lead, were not damaged ; but 

 the two stones which formed the 6th course were cracked, shivered, and frag- 

 ments thrown from them. The 7tli course consisted likewise of two solid 

 stones. These were burst from the spindle, which was, by the intervention of 



