CHALDRON

, of Coals, an English dry measure of capacity consisting of 36 bushels heaped up.

The chaldron of coals is accounted to weigh about 2000 pounds.—On ship board, 21 chaldrons of coals are allowed to the score.

CHAMBER of a Mortar, or some cannon, is a cell or cavity at the bottom of the bore, to receive the charge of powder.

It is not found by experience that chambers have | any sensible effect on the velocity of the shot, unless in the largest ordnance, as mortars or very large cannon. Neither is it found that the form of them is very material; a small cylinder is as good as any; though mathematical speculations may shew a preference of one form over another. But in practice, the chief point to be observed, is to have the chamber of a size just to contain the charge of powder, and no more, that the ball may lie colse to the charge; and that its entrance may point exactly to the centre of the ball.