OF THE THICKNESS OF THE COATING.
The coating should not be more than two fingers thick, it should be
laid on in four thicknesses over fine clay and then well fixed, and
it should be fired only on the inside and then carefully covered
with ashes and cow's dung.
OF THE THICKNESS OF THE GUN.
The gun being made to carry 600 Ibs. of ball and more, by this rule
you will take the measure of the diameter of the ball and divide it
into 6 parts and one of these parts will be its thickness at the
muzzle; but at the breech it must always be half. And if the ball is
to be 700 lbs., 1/7th of the diameter of the ball must be its
thickness in front; and if the ball is to be 800, the eighth of its
diameter in front; and if 900, 1/8th and 1/2 [3/16], and if 1000,
1/9th.
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