•<556 



• KNOWLEDGE ♦ 



[Oct. 31, 1884. 



THE WORKSHOP AT HOME. 



By a Working Man. 



IN treatiDg of tlie dovetail joint on p. 233, I mentioned 

 the "mitre and key :" I shall begin to-day by saying 

 something about mitreing. Now, a mitre-joint in carpentry 

 means one in which the faces in contact are at an angle of 

 45° with the length and width of the article in which they 

 occur, as in Fig. 20, where T is the top and S the side of a 



^ 



Ti". 20. 



Fis. 21. 



picture-frame, each bevelled off at the angle shown. If 

 each bevel is perfectly accurate, it is easily seen that each 

 of the four pieces of the frame will be truly square to the 

 adjacent and parallel to the opposite one. We have, then, 

 first got to cut them truly to this angle, and then to finish 

 them with a plane without destroying it. They are usually 

 cut in what is called a mitre-box, or mitre-block. Fig. 21 

 shows a mitre-block which the amateur can make for 

 himself. In it B B is a sound piece of li inch deal, with 

 its upper surface planed up very true and flat. This may 

 be a foot long and 7 inches wide. A block of beech-wood 

 preferably (but deal will do) of the same length, but 

 measuring 31 inches in width and depth when finished, 

 must also be very carefully planed up, with its sides 

 accurately at right angles, the square (Fig. 7, p. 154) being 

 •repeatedly applied to test it as the work proceeds. This 

 being worked up true is firmly attached to the face of the 

 base board by glue and screws, as shown at M M, with 

 •which, as seen, it forms a step. It must here be particu- 

 larly remarked that the depth from the top of the block, 

 M M, to the bottom resting on B, though given above as 

 3|iu., must not quite equal the depth of the blade of our 

 tenon-saw. Hence, if the latter measures less than this 

 from the teeth to the metal rib at the back, the height of 

 M M (not its width) must be reduced. It now remains 

 to make two saw-cuts (or " kerfs," as workmen call them), 

 as guides for our saw. The plan of the mitre-block shown 

 in Fig. 22 will explain the way of doing this. First, by the 



uid of our rule, square, and pencil, we draw the two squares 

 shown in the figure, of which each side will obviously be 

 Si in. long (that being the width of M M) upon it, and join 

 the two corners of these squares, I m, Im, by straight lines, 

 each of which will quite evidently be at an angle of 45° 

 with the top of the block. We now place the square 

 adjacent to the points 1 1, and draw the perpendiculars, I /', 



1 1', on the back of the block. Finally taking a sharp 

 saw, of which the blade is perfectly flat, we saw with 

 the utmost care down m 1 1\ through the block, M M 

 (the use of screwing as well as gluing now becomes 

 manifest), and a little way — say | in. or \ in. — into 

 B B. If now we want to cut a mitre, we simply 

 hold the piece of wood tightly against the face, /"/, of the 

 block, pass the saw into either of the guide-lines, and saw 

 right through it. By fitting a diagonal stop at the end 

 of a piece of board, as shown in Fig. 2-j, and turning a 



trying plane on its siue, with its bottom against the edge 

 of the board, the sawn ends may be smoothed up quite 

 true. 



As an easy lesson in mitreing, the beginner may try to 

 make a small picture-frame out of the cheap moulding to 

 be bought in many parts of London. Having determined 

 the dimensions of his frame, he must mark them off on the 

 moulding, and saw them in the mitre-box, as explained 

 above, lie must carefully study the direction of his mitres 

 though, noting that the inner edges of his frame must be 

 the shorter ones, or he may find that he has sawn two 

 parallel to each other on the same piece of wood ! In the 

 absence of the special cramps of the professional picture- 

 frame maker, he may nail strips of wood on to a plank, three 

 of them actually in contact with three of the sides of his 

 fiarae, and the fourth a little way from the other, and very 

 slightly inclined to it, driving a wedge-shaped piece of 

 wood, planed to a corresponding slight slope, between this 

 and the frame, after the latter has been glued up and put 

 together on the plank. When the glue is dry, a sawkerf 

 may be made in each comer, and a bit of glued veneer 

 driven in just as in our " mitre and key " work, on p. 233. 

 It may be taken that, for the purpose of the ordinary 

 amateur, the tenon and mortice, the dovetail and the mitre- 

 joints are the only ones he is at all likely to have occasion 

 for. 



DICKENS'S STORY LEFT HALF TOLD. 



A QUASI-SCIENTIFIC IXqClRY IN'TO 



THE MYSTERY OF EDWIN DROOD. 

 By Thomas Foster. 



{Continued from p. 342.) 



THE scenes within the Billickin serve to show how little 

 of his humorous power Dickens had lost — indeed, 

 they are as good as anything in the same style he ever 

 wrote : but they throw no light on the development of the 

 story. 



But the chapter significantly called The Dawx Again 

 (the first is called The Dawn, but one is the dawn of the 

 plot, the other the dawn of the discovery) is full of light. 



It shows us, first, Crisparkle and Jasper face to face, 

 Jasper as the denouncer and pursuer of Neville Landless 

 and Mr. Cri.=parkle as his consistent advocate and protector. 



