In modern timber-buildings, and partitions, the same names are still used for the same things, as in old carpentry, wherever the things themselves are empla,yed, except in a few instances, viz., the interdnees are now called interties ; the middle beam of the roof went by several names, as collar-beam, strut-beam, wind-beam, or top-beam ; but of these names, only that of is retained. At pres ent we have no thcrefnv neither timings nor shreddings are necessary as in Figure 2 ; the are now called window, or doorposts; the vertical timber hanging from the vertical angle of the roof, and sup porting the principals, went formerly under the names of or ; hut now it retains only the name of The nomenclature employed in London and its vicinity is here alluded to.
The timbers in the internal angles, at the meeting of the two inclined sides of a roof, were formerly called sleepers, but now they are termed or see Figure 2 ; in which may be seen also a method of finding the length of the hip. without making any plan of the roof.
Plate II. Figures 3. 4, 5, show the manner of finding lengths and backs of the hips, as at present. The discovery of this principle is generously ascribed to Mr. Pope, of Lon don, by the author now quoted.
Thus much for the wnrk published by Godfrey Richards.
The carpentry published in Maxon's Mechanical E.rer cises, contains nothing more than the names and applications of timbers, which are the same as those described by Godfrey Richards.
In The Art of Sound Building, Mr. l Ialfpenny shows the methods of tracing the of coves, regular and irregular groins, the common ribs in each return being of one common height.
The following specimens will show what has been done by this author. He likewise shows how to find the arch for the aperture of a window, of a given width and height so as the angles may he in vertical planes, according to legitimate principles; but he does not, in any instance, show the method of beveling the edge of the angle-ribs, so as to range with ribs fixed in the returns.
Plate 111. Figure 1. " To the angle or of a draw the base n of the regular bracket, and from A draw A n, perpendicular and equal to it, and draw the line n a, and continue the line n A to c, so that A c be also equal to A 13 then extending your compasses from A to n, and setting one foot in A, with the other describe the arch, (e- quarter of a circle c n, and from the point D draw ID F, perpendicular to D B, and equal to D A. or A C, and another as 13 E 11.1)111 B, likewise equal to D A. and draw the line F E, which will be parallel to n n. This being done, divide A B into a number of equal parts, not exceeding two inches and a halt, and through the divisions of them draw lines parallel to A c, to touch the arch c a, which continue out to the line n n, and this line will be divided likewise into the same number of equal parts as A B is. Lastly, from the divisions of the line D B, draw lines parallel to D F, and in each of them, from D B. lay off its respective parallel (from A n to the arch n c) and at the points whereat they end, stick small nails, or pins, and take a thin lath, and bend it round the nails, or pins, observing that it touches them all, and with a pencil, or any thing else proper to make a mark, describe the arch F B round the edges of the lath; and this is the arch for the angle or mitre bracket."
Figure 3, "If the lesser arch of an irregular groin be a given semicircle, it is required to form a larger one (not a semicircle) so that the intersection of those two arches shall beget, or make the arch-line of the angle to hang perpen dicular over its base ; as also to draw that arch-linc of the draw the lines A B and c n, to represent the walls from whence the arches spring, and draw the line c n, and on the line A c describe the semicircle A E c, and divide A c into any number of equal parts, from whence draw paral lel lines to c D, to touch or come to the arch A E c, and if these parallels are continued out to the line c n, they will divide it into the same number of equal parts as A and if from each of the divisions of this last line parallels to A C are drawn. they will divide the line A n into the same num ber of equal parts as A 0, or c n, is divided into. This being done, continue A C to so that A 1 he equal to El; and con tinue D B to X, so that X II be likewise equal to Ef,' or A I, and draw the liner K. Moreover, at the points c and is raise the perpendiculars c x and n o to c 13, each of the same length as E j; or A I, or B K, and draw the line x o. Lastly, from the divisions of A n, draw parallels to A i (that is, continue the parallels drawn from the divisions of the line c u to the line x) and from the divisions of c n parallels to c N. Then set off the heights or lengths of each of the parallels in the semicircle A E c, upon the correspondent parallels to A t and c x, and stick in nails whereat they terminate and if' a lath be bent round them, so as to touch them all, and a pencil be moved round the edge of it, the arches A II D and c N B will be tbund ; which was required to be done.
" Xote.—The pricked lines in this, and all other examples of this kind, show that one parallel line has a relation with the other. For example: the lines E, g / are all equal to one another ; so that if the three arches A n B, A E c, and c N 13, were raised perpendicularly upon the lines A B, A c, and c B, and a line drawn from is to N, and another from N to E • then would the line iv » be parallel to, and directly over the pricked line l g. In like manner, the line E 11 would be parallel to, and directly over the pricked line f 1. Under stand the same of the other parallels and pricked lines in this figure, and any others of the like nature." Figure 3.—" Haring one centre given for an unequal sided groin, to form the other, so that the intersection thereof shall produce the angle, or mitre-arch, to hang perpendi cularly over its base ; and, moreover, to draw the curve the lines A n and D D, and n c and c A, each equal to one another, to represent the walls from whence the arches spring. and on the line A 13 describe the given arch A F B. This being done, divide the line A B into any number of equal parts, from whence raise perpendiculars to A B to touch the arch A F a, and draw the diagonal lines A D and B c. Then take the line E F, and set it perpendicular to the lines