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PRACTICAL CONSTRUCTION.

Subdivision Fourth — Estimates and Calculations of Artificers’ Work of various hinds.

1776. The limits of the work prevent ns from giving full descriptions of themethods adopted in practice for estimating the quantities of materials used inbuilding. The subject is too elaborate to admit of this being done ; it will besufficient for our purposes if we give in brief abstract form a selection of calcu-lations and statements, which will enable our readers to form a rough estimate,sufficiently accurate for ordinary purposes, of the quantities of materials requiredfor any structure or part of a structure. The quantities being known, it will bean easy matter to ascertain from a tradesman the cost of supplying them, chargedin the usual w r ay.

1777. Section First — Diggers’ and Excavators' work is estimated by the cubicyard of 27 feet, or a “ single load.” Taking the cost of digging and throwingout common soil to a depth not exceeding 6 feet at 5d. per yard cube, the costof digging in gravel or clay will be 7d. A ton of excavated matter is equal to24 cubic feet of sand, 17 cubic feet of clay, 18 cubic feet of ordinary earth orsoil, 13 cubic feet of chalk.

1778. Well-Digging and Well-Steining with bricks is estimated by the foot indepth, the price varying according to the diameter. Thus, where the diameteris 3 feet, in clear of brickwork, and the price per foot in depth 13s., the pricefor a diameter of 6 feet will be 23s. 6d., or thereabouts. By multiplying thesquare of diameter of well, including brickwork, by "7854, the number of cubicfeet of earth obtained in digging each foot of depth will be ascertained. Bymultiplying the square of the diameter of well by "7854, and dividing the quo-tient by 6, the number of gallons of water contained in each foot of depth willbe ascertained.

1779. In Digging a Well 3 feet diameter in the clear, the quantity of earthremoved for every foot of depth is 11 cubic feet; of 4 feet diameter, 17 cubicfeet 17 in.; of 5 feet, 20 cubic feet; of 6 feet, 33 cubic feet 8 in.

1780. In Lining a Well with Brickwork (or steiningit, as it is technically termed)of 3 feet diameter ^ brick thick, the number of bricks required for every foot indepth is 57 laid in mortar, 68 laid dry ; where the lining is 1 brick in thick-ness the number required is 126 in mortar, 154 dry. For a well 4 feet diameter,the lining brick in thickness, the number of bricks for every foot will be 73in mortar, 89 dry ; 1 brick thick, 159 in mortar, 194 dry. For 5 feet diameter,£ brick lining, 90 in mortar, 110 dry ; 1 brick lining, 192 in mortar, 234 dry.For 6 feet diameter, | brick lining, 107 in mortar, 130 dry; 1 brick lining, 226in mortar, 276 dry.

1781. The number of Imperial Gallons contained in Wells of the following Diameterfor each Foot of Depth —3 feet diameter, 44 gallons; 4 feet, 78 ; 5 feet, 122 ;

6 feet, 176.

1782. Section Second. —In estimating the quantity of brickwork, ascertainby calculation the number of cubic feet in the wall; Reduce the number ofthese cubic feet so ascertained to the standard of brick and half, by multiply-ing them by 8 and dividing by 9; or find the area of the face of wall in feet,multiply the number of feet thus found by the number of half-bricks in thethickness of the wall; divide the result by 3, which will give the superficialfeet; divide the amount by 272, and the result is the number of “ rods ” of thestandard thickness.