180 = Conversion of Cannon Bails into Plumbago. 
was observed to be soft, and when cut, presented every ap- 
pearance of perfect black lead, exactly like that in the New- 
Haven ball which Capt. Phipps bas examined. He found 
no difficulty in boring into the ball, quite to the centre, where 
he found it solid, as it was also in every other part. The 
perforation which he made, was funnel-shaped, or conical, 
two inches wide at the outside and tapering to the vertex in 
the centre. He is firmly persuaded that the oysters had 
produced the change, and thinks that there must have been 
oysters adhering to the ball recently found at New-Haven. 
Of this there is no direct evidence, although it is said there 
were shells in the bank where it was found. Both balls 
were evidently found under circumstances considerably sim- 
ilar, and carbon might possibly have been afforded to the 
iron, both by the mud and the oysters. ‘The facts are curi- 
ous, and we have thought them worth preserving. 
Captain Phipps farther states the following circumstance, 
which is not easily explained upon the suggestions made 
above. He was employed during the war of the American 
revolution, to clear an old cannon, which was covered out- 
side and in, with oyster shells adhering firmly to it. On re- 
moving them, the metal was discovered to be perfectly 
sound, and no change had occurred similar to that in the 
cannon balls. But it is obvious that this cannon must have 
lain long under the salt water, although it might not have 
been in mud, for it was not known whence it was brought. 
A circumstance occurred during the cleaning of this can- 
non, which was very remarkable. As one means of detach- 
ing the shells, a fire was built around the cannon, and it was 
elevated, and directed in sport at the chimney of a common 
man, ludicrously called the Governor, with a threat to blow 
the Governors chimney down. At the end of two hours the 
cannon actually went off witha greatreport, and knocked the 
chimney down. It would seem that the cannon must have 
been loaded, and probably spiked, by which means and the 
wadding, the powder, although wet, was kept in its place, 
until by the heat, it became sufficiently dried to explode, and 
carried the ball against the chimney. It is scarcely neces- 
sary to add that it effectually cleared the cannon of the oys- 
ter shells. 
