C JI 3 ] 
An Account of the Mariners Compa fs, that was 
Jtruck with Lightning, and fljewn at the lafl 
Meeting of the Royal Society ; with fome further 
‘Particulars relating to that Accident } commu- 
nicated by Gowin Knight, M. B. F. R. S. 
TT7HEN I came to examine the Compafs ftruck 
with Lightning, I obferved that the outward 
Cafe was joined together with Pieces of iron Wire, 
1 6 of which were found in the Sides of the Box, 
and io in the Bottom. I applied a fmall Needle to 
each of thefe Wires, and immediately perceived that 
the Lightning had made them ftrongly magnetical; 
particularly thofe that joined the Sides. All the 
Heads of the Wires on one Side of the Box attraded 
the North Point of the Needle, and repelled the 
South; vvhilft all the Heads on the other Side at- 
traded the South and repell’d the North. The Wires 
at the Bottom attraded the South and repelled the 
North ; but it is not certain, whether this Polarity 
was any-ways owing to the Lightning ; lince it might 
be acquired by their continuing long in an ered 
Pofture. 
In examining the Card, I found the Needle was 
vigorous enough in performing its Vibrations, but 
that its Polarity was inverted j the North Point turn- 
ing conftantly to the South. I then tried to take 
out the Card, to examine the State and Strudure of 
the Needle: But the Jundurcs were every-where 
well-fccured with Putty, and that grown fo hard, 
that I was obliged to ufc fome Violence, and at lad 
broke the Glafs. The Needle (if 1 may fo call it) 
P confided 
