The two celebrated Italian authors, Serlio and Palladio, have given designs in carpentry. The British authors who have written on this useful art, are Godfrey Richards, at the end of his Translation of the First Bonk of Andrew Palladio, third edition printed 1676; Moxon's Mechanical Exercises, second edition printed 1b93; falflienny's Art of Sound Buildiny, printed 17'25; The Carpenter's Companion, by Smith. printed 1733; Masonry, by Batty Lang ley, printed 1733 ; The British Carpenter, by Francis Price, printed 1735; The Gentleman's' and Builder's Repository, bs Edwarol Iloppus, printed 1738 ; The Builder's Complete Assistuo, by Batty Langley, printed in 1738; The Builder's Workman's Treasu•y, by Batty Langley, printed in 1711; The Builder's Jewel, by the same author; The Lon don Art of Building, by William Salmon, the third edition, printed in 1718; The British Architect, by Abraham Swan, second edition printed in 1750; Designs in Carpentry, by the same author, printed in 1759; several pieces ofearpentry, in A Complete Body of Architecture, written by Isaac Ware, published in 1763 • The Carpenter's and Joiner's Repository, by William Pain, printed in 1778; The Carpenter's Pocket Directory, by the same author, printed in 1780; 7'he Golden Rule, by the same, printed in 1781; The British Palladio, by the same, printed 1788 ; The Practical Builder, by the same author ; The Practical house Carpenter, by the same author, printed in 1791. The following are 'productions of the Author of the present Work : The Carpenter's Sew Guide, in 179!1 ; The Carpenter's and Joiner's Assistant, printed in 179•1. Likewise, the various articles on carpentry, in Rees' Cyclopedia ; A Treatise on Carpentry, in the Edinburgh Encycloprrdia ; and a treatise on the same subject, in his Mechan•al Exercises. A article on Carpentry, iu a SlIflplement to the Encyclopedia Britannica, was written by Professor Robison, of Edinburgh; and an article on Carpentry, in Course of Lectures on Natural Philosophy and the Mechanical Arts, by Thomas Young, Al. I)., late Professor of Natural Philosophy in the Royal Institution of Great Britain.
"We shall here give extracts from these authors, in order to mark the various methods and progressive improvements in the scientific and practical parts of carpentry, particularly that part which relates to geometrical description.
Godfrey Richards, in his general title, at the end of the translation above referred to, writes thus : " Of lioqls.—thiles and instructions for framing all man ner of roofs, whether square or bevel, either above or under pitch, according to the best manlier practised in England.
Also to find the length of the hips and sleepers, with the back or hip mould, never yet published by any architect, modern or antique ; a curiosity worth the regard, even of the most curious workman ; exactly demonstrated in the following rules and designs, by that ingenious architect, Alr. William Pope, of London.
"Having raised the walls to their designed height, and made the vaults, laid the joists, brought up the stairs. and
performed all those things spoken of before ; we are now to raise the root; which embracing every part of the building, and with its weight equally 'pressing upon the walls, is a band to all the work ; and besides defends the inhabitants from rain, from snow, from the burning sun, and from the moisture of the night ; adds no small help to the building, casting off from the walls the rain water, which although for a while it seems to do but little hurt, yet in process of time is the cause of much damage. The first men (as saith Vitruvius) built their houses with Ilat root's, but finding that thereby they were not defended from the weather, they (constrainer) by necessity) began to make them ridged (that is to say) raised in the middle. These roofs are to be raised to a higher or lower pitch, according to the country in which they are ; wheretbre in Gct.many, by reason of the great quantity of snow that falls there, they raise their roofs to a very great pitch, and cover them with shingles, which are small pieces of wood, or of thin slate or tiles ; for it' they should raise them otherwise, they would be ruined by reason of the weight of the snow. But we, who dwell iu a more temperate country, ought to choose such a pitch as may secure the building, and be ofa handsome form : thet.efore we divide the breadth of the roof into four equal parts, and take three, which makes the most agreeable pitch for our country, and is the foundation for the raising of any manner of roof, whether square or bevel ; as appears in the following designs and descriptions." So will o x and a 1: make the length of the ridge 1 F ; and x D and c N. the two skirts.
" To find the length of the hip.—Draw the diagonal line r and 1 c, over which the hip is to hang when in its due place.; then take the perpendicular line E F, and place it from the point r to r r, perpendicular to the diagonal or base lines D r and t c, at r; so is t r and r r, the pitch of the hip, equal to the gable end, E F: and when erected, will hang perpen dicular to the point t; then n, the hypothennse of the triangle D I P, and c r, the hypothenuse of the triangle c placing them from D to o, and c to G gives the length of the hip D G c, and when laid to their pitch, will all meet perpen dicular to the point T.
" To find the back of the hip, so that it may answer both sides and ends of the roof; whether square or bevel.—Lay the ruler from the point L to the point n, and from the point n to N, and mark where it cuts the diagonal lines D r and r c at Q Q; then set one foot of the compasses on the point Q, and extend the other foot to the hip lines D P and c r, at the nearest distance; with that, mark the points upon the same diagonal lines; then draw the pricked lines L R n and ti R xr, which make the back of the hip for the two corners of that roof.
" This rule serves for all roofs, whether over or under pitch." Figure 4.—" Of roofs bevel at one end, and square at the other ; the gable end square, and the bevel end hipped.