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Rebating is the reducing of a piece of timber, by takingaway a prism at the angle, so as to leave only two sides,each of a parallel breadth, forming an internal angle, gene-rally a right angle: so that in grooving and rebating, thegroove or rebate is always less than the original depth ofthe stuff or piece out of which it is formed. The latteroperation is particularly used in door-cases and the framesof casement-windows ; the rebate forming a kind of ledgefor the door or casement to stop against.

The implements which the carpenter has occasion toemploy in the several operations, will be seen under thehead Tools.

The principal operations, after the pieces are formed,consist in the joining of timbers: two pieces of timber maybe joined so as to form either one, two, or four angles,oblique or right. A notched joint is formed by cutting outof the thickness of each piece, a part in the form of aparallelopiped ; so that when the two pieces are joined, thesubstance left at the reduced thickness of the one piece, fillsthe excavation of the other, as far as it goes into its depth.If the thickness of the part left be equal to that of the parttaken away in each piece, and the thickness of the part leftof the one piece be equal to the thickness of the part left ofthe other piece, the joint is then said to be halved. Inmaking one angle, the recess or excavation is formed at the\ end of each piece, and consists of two plane surfaces, one| perpendicular, the other parallel to the two opposite faces,

! and in the plane of the angle. In forming two right angles,

I one piece must, of course, project on both sides of the other,and the other only on one side ; the excavation or recessi made in that which projects on both sides, consists of threeplane surfaces, one being parallel, and the other two at rightangles to the faces ; the excavation or recess made in thatwhich projects on one side, consists of two plane surfaces,in the like positions. In forming four right angles, thenotch of each piece consists of three sides, two of which areat right angles, and the other parallel to the faces. Onepiece of timber may also be joined to another, so as to formonly one or two adjacent angles, by notching one piece onthree sides at the ends, and so forming a projecting prism,called a tenon, the sides of which are respectively parallelto the sides of the piece, and by excavating the end of theother piece, to receive the tenon, which is made to fit exactly.The two pieces thus formed at one or more angles to eachother, may, if found necessary, be fixed by means of woodenpins, or nails, spikes, screws, bolts, straps, or other metalfastenings.

The two celebrated Italian authors, Serlio and Palladio,have given designs in carpentry. The British authors whohave written on this useful art, are Godfrey Richards, atthe end of his Translation of the First Booh of AndrewPalladio, third edition printed 1676; Moxon’s MechanicalExercises, second edition printed 1693; Halfpenny’s Art ofSound Building, printed 1725 ; The Carpenter's Companion,by Smith, printed 1733; Ancient Masonry, by Batty Lang-ley , printed 1733; The British Carpenter, by Francis Price,printed 1735 ; The Gentleman!s and Builder’s Repository,by Edward Hoppus, printed 1738; The Builder's CompleteAssistant, by Batty Langley , printed in 1738 ; The Builder’sand Workman’s Treasury, by Batty Langley , printed in1741; The Builder’s Jewel, by the same author; The Lon-don Art of Building, by William Salmon , the third edition,printed in 1748; The British Architect, by Abraham Swan,second edition printed in 1750; Designs in Carpentry, bythe same author, printed in 1759; several pieces of carpentry,in A Complete Body of Architecture, written by Isaac Ware ,published in 1768; The Carpenter’s and Joiners Repository ,

by William Pain, printed in 1778 ; The Carpenter's PocketDirectory, by the same author, printed in 1780; The GoldenRule, by the same, printed in 1781; The British Palladio,by the same, printed 1788; The Practical Builder, by thesame author; The Practical House Carpenter, by the sameauthor, printed in 1791. The following are productions ofthe Author of the present Work: The Carpenter’s NewGuide, in 1792; The Carpenter’s and Joiner's Assistant,printed in 1792. Likewise, the various articles on carpentry,in Rees’ Cyclopedia; A Treatise on Carpentry, in theEdinburgh Encyclopedia; and a treatise on the same subject,in his Mechanical Exercises. A long article on Carpentry,in a Supplement to the Encyclopedia Britannica, was writtenby Professor Robison, of Edinburgh ; and an article onCarpentry, in A Course of lectures on Natural Philosophyand the Mechanical Arts, by Thomas Young , M. D. lateProfessor of Natural Philosophy in the Royal Institutionof Great Britain.

We shall here give extracts from these authors, in orderto mark the various methods and progressive improvementsin the scientific and practical parts of carpentry, particularlythat part which relates to geometrical description.

Godfrey Richards, in his general title, at the end of thetranslation above referred to, writes thus :

“ Of Roofs. —Rules and instructions for framing all man-ner of roofs, whether square or bevel, either above or underpitch, according to the best manner practised in England.

“ Also to find the length of the hips and sleepers, withthe back or hip mould, never yet published by any architect,modern or antique; a curiosity worth the regard, eventhe most curious workman; exactly demonstrated in thefollowing rules and designs, by that ingenious architect,Mr. William Pope, of London .

“ Having raised the walls to their designed height, an'lmade the vaults, laid the joists, brought up the stairs, andperformed all those things spoken of before; we are now t0raise the roof, which embracing every part of the buildingsand with its weight equally pressing upon the walls, is 9band to all the work; and besides defends the inhabitantsfrom rain, from snow, from the burning sun, and from themoisture of the night; adds no small help to the building;casting olf from the walls the rain water, which althoughfor a while it seems to do but little hurt, yet in process o*time is the cause of much damage. The first men (as said 1Vitruvius ) built their houses with flat roofs, but finding tha*thereby they were not defended from the weather, the/(constrained by necessity) began to make them ridged (tl‘ ll jis to say) raised in the middle. These roofs are to be raise 9to a higher or lower pitch, according to the country in whic‘‘they are; wherefore in Germany , by reason of the g re9quantity of snow that falls there, they raise their roofs to 9very great pitch, and cover them with shingles, which aiesmall pieces of wood, or of thin slate or tiles; for ifshould raise them otherwise, they- would be ruined by reaso”of the weight of the snow. But we, who dwell in a m 91temperate country, ought to choose such a pitch as may secu*the building, and be of a handsome form: therefore we div)the breadth of the roof into four equal parts, and take thru*which makes the most agreeable pitch for our country;is the foundation for the raising of any manner of ’whether square or bevel; as appears in the following desig 9and descriptions.”

“ The manner of framing a floor, with the names of eCtC

member. (See Carpentry, Plate I. Figure 1.

“ 1. The thickness of the wall, and lintel or wall-p 19te rand if it be in timber-work, then a bressummer