Page:Philosophical Transactions - Volume 054.pdf/273

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[ 215 ]

The operation and progress of the lightning in the obelisk and upper parts of the steple 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 octonogal
obelisk
22 3
Length of the iron spindle 19 9
Thickness of the spindle, where
inserted into the stone.
0 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.
11 5
From the first concealed chain one
foot above the base of the
obelisk to the first cross chain.
2 0
From the first cross chain to the
second, 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 ten 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 thestones,