524 nairne on the Jhortening 
great furprize, they found the bolt drawn up ; and on trying 
to pull it down, they could not with all their drength. It 
being a particular acquaintance of mine, they fent for me. I 
went the next day, and not only found the bolt drawn up, but 
the wire, which they told me before was very loofe, and much 
bent, was drawn very draight, and fo tight, that when druck 
it produced a mufical tone. The wire was judged to be 
ihortened feveral inches ; for, had the wire before the accident 
been draight, it mull have fhortened it above two inches to 
have drawn the bolt up. 
The whole length of the wire from the bed-fide to the bolt 
was about thirty feet ; but the part of the wire on which the 
lightning palled was about fifteen feet. 
Near the crank iron that was directly over the bolt were two 
wires, which palled through the wainfcot to a lingle one be- 
longing to an alarm. The lightning palled thefe two wires, 
without damaging them ; but the lingle one was partly dilperfed 
into fmoke, blackening all the wainfcot near it; alfo a great deal 
was melted into globules, which globules we found by a magnet. 
This was the fird indance (and, I mud own, it agreeably 
furprized me) that I had ever met with of wire being con- 
tracted or Ihortened by the effeCt of lightning, though I have 
now not the lead doubt, but that it is always the cafe ; and 
that is the reafon that we find them modly broke where the. 
ghtning has palled, if it does not melt them. I have often 
Ihortened wire by electricity, an account of which I gave to 
the Royal Society as before mentioned. 
I have brought a piece of wire belonging to the night-bolt, 
and alfo fome of the globules, for the infpeCtion of the Society. 
I have the honour to be-, &c. 
POST- 
