43

32

of of an inch thick; after the rate of 18 fhillings

a hundred weight.

length
breadth

57

2

114

9°373

342

798

342

798

weight in lb.

- 840°522

840'522

143671978 whole weight in pounds, which being divided by 112 gives 128 2855 cwt. for the weight of the whole, which at 18 fhillings the cwt. comes to £115 9 1 for the expence required.

CHAPTER XII.

GENERAL ILLUSTRATION.

Having gone through the measurable parts of a building, &c. and noted the methods of measuring them, and of computing the contents; I proceed now to the general illuftration of the whole, by af figning the dimenfions of a house, and from thence -computing the contents of the feveral different kinds of works fuppofed to be used in it; in the performing of which are fhewn the methods of ruling the book and entering the dimenfions with the contents, then the method of abstracting the contents,

and

and laftly of forming the bills of the expences of the work and materials. At the end of this chapter is given a plate containing the elevation and plans of the feveral ftorys of the house, accurately delineated from a particular fcale, inferted in the plate; by which the reader may, with a pair of compaffes, measure and compare the dimenfions of moft of the articles as he proceeds through them. In this example is used a houfe of only two ftorys and two rooms on each floor, as thofe are very fufficient for explaining the feveral methods and works here treated of.

The columns of numbers in the following forms are fufficiently explained by the titles at the tops of them; excepting the figures 2, 3, &c. in the first column, and prefixed to the dimensions, the meaning of which figures is, that the contents arifing from the dimenfions to which they are prefixed, are to be multiplied by 2, 3, &c. and then fet down in the column of contents.

The DIGGING of the CELLARS.

Feet In.

54 o length
28 6. breadth

8 o depth

which three dimenfions, being multiplied continually together, produce 12096 cubic feet, which being divided by 27, the cubic feet in a yard, there refult 448 cubic yards of digging.

8 0

112

Out walls of the principal and attic ftory.

7 1176 0 Middle walls of ditto.

Chimney fhafts within the

roof.

To abftract the foregoing particulars, that is, to
collect together the contents of the fame kind, re-
duce their fums to the ftandard thickness of a brick
and a half, and then, having made the deductions,
to collect the reduced fums, to obtain the whole in
one fum, I proceed thus: I make only two columns
for the whole contents, and two for the deductions
of the fame thicknefs, viz. one column for the one
brick contents, and the other for the brick and half
contents; and difpofe the fuperior denominations
in one or both of thefe columns by placing them
down more than once; thus, the contents of 2 bricks
thick I fet down twice in the one brick column;
thofe of 2 bricks, I fet down once in the one brick
column and once in the brick-and-half column ;
thofe of bricks, twice in the brick-and-half co-
lumn; thofe of 3 bricks, once in the brick-and-
half, and twice in the one brick column; and thofe
of four bricks, twice in the brick-and-half and once
in the one brick column; and fo on if there were
higher denominations; and, laftly, for the contents
of half a brick thick, I take the halves of them and
fet in the one brick column. Then, having added
up every column, I reduce the fums of the one brick
thick to the brick and half thickness; and add this
reduced content to the brick and half fums, both
in the folids and deductions; then, laftly, take the
one fum from the other for the whole content of
the brick work, as below.

The