In the foundations of buildings, Vitruvius orders the ground to be dug up, to examine its firmness; that an apparent solidity is not to be trusted, unless the whole mould cut through be sound and solid: ’tis true, he does not say to what depth it should be dug: but Palladio determines it to be a sixth part of the height of the building.
The great laws of walling are:—1. That the walls stand perpendicular on the ground-work, the right angle being the foundation of all stability. 2. That the largest and heaviest materials be the lowest, as more proper to sustain others than be sustained themselves. 3. That the work diminish in thickness, as it rises, both for the ease of weight and to lessen the expence. 4. That certain courses, or lodges, of more strength than the rest, be interlaid, like bones, to sustain the wall from total ruin, if some of the under parts chance to decay. 5. Lastly, that the angles be firmly bound, they being the nerves of the whole fabric. These are sometimes fortified on each side the corners, even in brick buildings, with square stones; which add both beauty and strength to the edifice. See [Stone], [Bricks], [Lime], [Sand].
BULLETIN, Fr. any official account which is given of public transactions. See [Gazette].
BULLETS, are leaden balls, wherewith all kinds of small fire-arms are loaded. The diameter of any bullet is found, by dividing 1.6706 by the cube root of the number, which shews how many of them make a pound; or it may be done in a shorter way. From the logarithm .2228756 of 1.6706 subtract continually the third part of the logarithm of the number of bullets in the pound, and the difference will be the logarithm of the diameter required.
Thus the diameter of a bullet, whereof 12 weigh a pound, is found by subtracting .3597270, a third part of the logarithm of 12, from the given logarithm .2228756, or, when the logarithm is less than the former, an unit must be added, so as to have 1.2228756, and the difference .8631486 will be the logarithm of the diameter sought, which is .7297 inches; observing that the number found will always be a decimal, when the logarithm, which is to be subtracted, is greater than that of one pound; because the divisor is greater than the dividend in this case.
Hence, from the specific gravity of lead, the diameter of any bullet may be found from its given weight: for, since a cube foot weighs 11325 ounces, and 678 is to 355 as the cube 1728 of a foot, or 12 inches, is the content of the sphere, which therefore is 5929.7 ounces: and since spheres are as the cubes of their diameters; the weight 5929.7 is to 16 ounces, or 1 pound, as the cube 1728 is to the cube of the diameter of a sphere which weighs a pound; which cube therefore is 4.66263, and its root 1.6706 inches, the diameter sought.
The diameter of musket bullets differs but ¹⁄₅₀th part from that of the musket bore; for if the shot but just rolls into the barrel, it is sufficient. The English allow 11 bullets in the pound for the proof of muskets, and 14 in the pound, or 29 in two pounds, for service; 17 for the proof of carbines, and 20 for service; and 28 in the pound for the proof of pistols, and 34 for service. The proof bullet of the U. S. musket made at Harper’s ferry in Virginia, the barrel of which is 3 feet 8³⁄₄ inches, is one fifteenth of a pound; the service ball one nineteenth. The Rifle of Harper’s ferry, the barrel of which is 2 feet 10 inches; the proof ball is one twenty-eighth of a pound; the service ball is one thirty-secondth part of a pound. See [Gun] and [Rifle].
Hollow Bullets, or shells, of a cylindrical shape. These have an opening and a fuze at the end, by which fire is communicated to the combustibles within, and an explosion takes place, similar to that occasioned by the blowing up of a mine.
Chain Bullets, are two balls which are joined together by a chain, at any given distance from each other.
Branch Bullets, two balls joined together by an iron bar.