The British seldom use any of lower calibre than 6 in the field. The metal of which brass cannon is made, is in a manner kept a secret by the founders; yet, with all their art and secrecy, they have not hitherto found out a composition that will stand a hot engagement without melting, or at least being rendered useless. Those cast at Woolwich bid fair towards this amendment. The respective quantities which should enter into this composition, is a point not decided; every founder has his own proportions, which are peculiar to himself. The most common proportions of the ingredients are the following, viz. To 240lb. of metal fit for casting, they put 68lb. of copper, 52lb. of brass, and 12lb. of tin. To 4200lb. of metal fit for casting, the Germans put 3687³³⁄₄₁lb. of copper, 204¹³⁄₄₁lb. of brass, and 307³⁶⁄₄₁lb. of tin. Others again use 100lb. of copper, 6lb. of brass, and 9lb. of tin; and lastly, others 100lb. of copper, 10lb. of brass, and 15lb. of tin. With respect to iron guns, their structure is the same as that of the others, and they generally stand the most severe engagements, being frequently used on shipboard. Several experiments have taught that the Swedish iron guns are preferable to all others in Europe. CANNON is now generally cast solid, and the cavity bored afterwards by a very curious machine for that purpose, where the gun is placed in a perpendicular position; but of late these machines have been made to bore horizontally, and much truer than those that bore in a vertical form. This new machine was first invented at Strasburg, and greatly improved by Mr. Verbruggen, a Dutchman, who was head founder at Woolwich, where probably the best horizontal boring machine in Europe has been lately fixed; it both bores the inside, and turns and polishes the outside at once. For length and weight of French and English cannon see GUNS. _Names of the several Parts of a_ CANNON. _The grand divisions exterior_, are as follows, viz. _First re-inforce_, is that part of a gun next the breech, which is made stronger, to resist the force of powder. _Second re-inforce._ This begins where the first ends, and is made something smaller than the first. _The chace_, is the whole space from the trunnions to the muzzle. _The muzzle_, properly so called, is the part from the muzzle astragal to the end of the piece. _Small divisions exterior._ _The cascable_, the hindermost part of the breech, from the base-ring to the end of the button. _The cascable-astragal_, is the diminishing part between the two breech mouldings. _The neck of the cascable_, is the narrow space between the breech moulding and the button. _The breech_, is the solid piece of metal behind, between the vent and the extremity of the base-ring, and which terminates the hind part of the gun, exclusive of the cascable. _The breech-mouldings_, are the eminent parts, as squares or rounds, which serve only for ornaments to the piece, &c.