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These four lines are logarithmic ones, and the three A, B, C, which are all equal to one another, are double lines, as they proceed iwice over from 1 to 10. The other or lowest line, d, is a single one, proceeding from 4 to 40. It is also called the girt line, from its use in computing the contents of trees and timber; and on it are marked wg at 17:15, and AG at 18:95, the wine and ale gage points, to make this instrument serve the purpose of a gaging rule.
On the other part of this face, there is a table of the value of a load, or 50 cubic feet, of timber, at all prices, from 6 pence to 2 shillings a foot.
When I at the beginning of any line is accounted 1, then the 1 in the middle will be 10, and the lo at the end 100; but when I at the beginning is counted 10, then the 1 in the middle is 100, and the 10 at the end 1000; and so on, And all the smaller divisions are altered proportionally.
II. ARTIFICERS' WORK.
square feet' :
ARTIFICERS compute the contents of their works by several different measures. As, Glazing and masonry, by the foot ; Painting, plastering,
paving, &c by the yard, of 9 square feet : Flooring,
partitioning, foofing, tiling, &c. by the square of 100 And brickwork, either by the yard of 9 square feet, or by
the perch, or square rod or pole, containing 272 square feet, or 30 square yards, being the square of the rod
or pole of 16 feet or 5 yards long. As this number 2724 is troublesome to divide by, the is often omitted in practice, and the content in feet divided only by the 272
All works, whether superficial or solid, are computed by the rules proper to the figure of them, whether it be a triangle, or rectangle, a parallelopiped, or any other figure.
III. BRICKLAYERS' WORK
BRICKWORK is estimated at the rate of a brick and a half thick. So that if a wall be more or less than this standard thickness, it must be reduced to it, as follows:
Multiply the superficial content of the wall by the number of half bricks in the thickness, and divide the product by 3.
The dimensions of a building may be taken by measuring half round on the outside and half round it on the inside ; the suin of these two gives the compass of the wall, to be multiplied by the height, for the content of the materials.
Chimneys are commonly measured as if they were solid, deducting only the vacuity from the hearth to the mantle, on account of the trouble of them. All windows, doors, &c. are to be deducted out of the contents of the walls in which they are placed. .
EXAMPLES. Exam. 1. How many yards and rods of standard brickwork are in a wall whose length or compass is 57 feet a inches, and height 24 feet 6 inches; the wall being 23 bricks or 5 half-brieks thick ? Ans. 8 rods, 17 yards.
Exam. 2. Required the content of a wall 62 feet 6 inches long, and 14 feet 8 inches high, and 2 bricks thick?
Ans. 169.753 yards. Exam 3. A triangular gable is raised 17 feet high, on an end wall whose length is 24 feet 9 inches, the thickness being 2 bricks : required the reduced content?
Ans. 32.08} yards. Exam. 4. The end wall of a house is 28 feet 10 inches long, and 55 feet 8 inches high, to the eaves ; 20 feet high is 2} bricks thick, other 20 feet high is 2 bricks thick, and the remaining 15 feet 8 inches is 1: brick thick; above which is a triangular gable, of i brick thick ; which rises 42 courses of bricks, of which every 4 courses make a foot. What is the whole content in standard measure ? Ans. 253 626 yards.
IV. MASONS' WORK.
To masonry belong all sorts of stone-work; and the measure made use of is a foot, either superficial or solid.
Walls, columns, blocks of stone or marble, &c. are measured by the cubic foot ; and pavements, slabs, chimney. pieces, &c. by the superficial or square foot.
Cubic or solid measure is used for the materials, and square measure for the workmanship.
In the solid measure, the true length, breadih, and thickness are taken, and multiplied continually together. In the superficial, there must be taken the length and breadth of every part of the projection which is seen without the general upright face of the building.
Exam. 1. Required the solid content of a wall, 53 feet 6 inches long, 12 teel 3 inches high, and 2 feet thick ?
Ans. 1310 leet. Exam. 2. What is the solid content of a wall, the length being 24 feer 3 inches, height 10 feet 9 inches, and 2 feet thick ?
Ans. 521.375 feet. Exam 3. Required the value of a marble slab, at 88. per foot; the length being 5 feet 7 inches, and breadth I loot 10 inches?
Ans. Al. 18. 101d. Exam 4. In a chimney-piece, suppose the length of the mantle and slab, each 4 feet 6 inches breadth of both together
3 2 length of each jamb breadth of both together
1 9 Required the superficial content ? Ans. 21 feet 10 inches,
V. CARPENTERS' AND JOINERS' WORK.
To this branch belongs all the wood-work of a house, such as fi oring, partitioning roofing, &c.
Large and plain articles are usually measured by the square foot or yard, &c.; but enriched mouldings, and some otner articles, are often estimated by running or lineal measure ; and some things are rated by the piece.
In measuring of Joists, take the dimensions of one joist, and multiply its content by the number of them ; considering that each end is let into the wall about is of the thickness, as it ought to be.
Partitions are measured from wall to wall for one di. mension, and from floor to floor, as far as they extend, for the otber.
The measure of Centering for Cellars is found by making a string pass over the surface of the arch for the breadth, and taking the length of the cellar for the length : but in groin centering, it is usual to allow double measure, on account of their extraordinary trouble.
In Roofing, the dimensions as to length, breadth, and depth, are taken as in flooring joists, and the contents computed the same way.
In Floor-boarding, take the length of the room for one dimension, and the breadth for the other, to multiply together for the coment. For Stair-cascs, lake the breadth of all the steps, by making
a line ply close over them, from the top to the bottom, and multiply the length of this line by the length of a step, for the whole area.-By the length of a step is meant the length of the front and the returns at the two ends ; and by the breadth is to be understood the girts of its two outer surfaces, or the tread and riser.
For the Balustrade, take the whole length of the upper part of the hand-rail, and girt over its end till it meet the top of the newel post, for the one dimension ; and iwice the length of the baluster on the landing, with the girt of the hand-rail, for the other dimension.
For Wainscoting, take the compass of the room for the one dimension ; and the height from the floor to the ceiling, making the string ply close into all the mouldings, for the other.
For Doors, take the height and the breadth, to multiply them togetiser for the area. If the door be panneled on both sides, take double its measure for the workmanship; but if one side only be panneled, take the area and its half for the workmanship.--For the Surrounding Archirave, girt it about the uppermost part for its length; and measure over it, as far as it can be seen when the door is open, for the breadth.
Window-shutters, Bases, &c. are measured in like manner.
In measuring of Joiners' work, the string is made to ply close into all the mouldings, and to every part of the work over which it passes.
Exam. 1. Required the content of a floor, 48 feet 6 inches long, and 24 fcei 3 inches broad? Ans. 11 sq. 764 feet.
Exam. 2. A floor being 36 feet 3 inches long, and 15 feet 6 inches broad, how many squares are in it?
Ans. 5 sq. 98} feet. Exam. 3 How many squares are there in 173 feet 10 inches in length, and 10 feet 7 inches height, of partitioning?
Ans. 18 3973 squares. Exam. 4. What cost the roofing of a house at 108. 6d. a square ; the length within the walls being 52 feet 8 inches, and the breadth 30 feet 6 inches ; reckoning the roof of of the flat ?
Ans. 121, 128, 11d.
Exam. 5. To how much, at 68. per square yard, amounts the wainscoting of a room ; the height, taking in the cornice and mouldings, being 12 feet 6 inches, and the whole compass 83 feet 8 inches ; also the three window-shutters are each 7 feet 8 inches by 3 feet 6 inches, and the door 7 feet by 3 feet 6 inches ; the doors and shutters, bring worked on both sides, are reckoned work and half work ?
Ans. 361, 12s. 2 d.
VI. SLATERS' AND TILERS' WORK.
In these articles, the content of a roof is found by multiplying the length of the ridge by the girt over from eaves to eaves; making allowance in this girt for the double row of slates at the bottom, or for how much one row of slates or tiles is laid over another.
When the roof is of a true pitch, that is, forming a right angle at top; then the breadth of the building, with its hall added, is the girt over both sides nearly.
In angles formed in a roof, running from the ridge to the caves, when the angle bends inwards, it is called a valley ; but when outwards, it is called a hip.
Deductions are made for chimney shafts or window holes.
Exam. 1. Required the content of a slated roof, the length being 45 feet 9 inches, and the whole girt S4 feet 3 inches?
Ans. 1744 yards. EXAM 2. To how much amounts the tiling of a house, at 258. 6d. per square; the length being 43 feet 10 inches, and the breadth on the flat 27 feet 5 inches; also the eaves projecting 16 inches on each side, and the roof of a true pitch?
Ans. 241. 98. 544.
VII. PLASTERERS' WORK.
PLASTERERS' work is of two kinds ; namely, ceiling, which is plastering on laths ; and rendering, which is plastering on walls : which are measured separately.