To put the members of the body together, lay the skin upon the floor on its back, in the same general shape as shown in Plate VI. Put the body board in place and mark the points where the ends of the leg irons strike it. Now for the iron squares.
The old and antiquated way to fasten leg irons to a centre board consisted in leaving a long end projecting, bending it like the letter U, and stapling it to the board. That was always a poor way, and in the light of a perfect arrangement it now seems poorer than ever.
When Mr. John Martens came over from Hamburg to work as a mammal taxidermist in Professor H.A. Ward's great Natural Science Establishment, at Rochester, N.Y., the most valuable luggage he brought with him was the idea of the iron square for attaching leg irons to a centre board. For that particular purpose it would be hard to devise a more perfect arrangement, and I shall be at some pains to describe it.
It requires four irons to fasten the legs to the centre board, one for each leg, and to make a set for an animal the size of a large mountain sheep ram, proceed as follows:
Procure four pieces of flat bar iron, 1/4 of an inch thick, 1-1/4 or 1-1/2 inch wide, and 9 inches long. At a point 3-1/2 inches from one end, bend each iron at a perfect right angle, which, of course, can only be done by heating it. Now heat the short arm red hot, clamp the end of it in a vise, and make a twist of exactly a quarter of a turn in the short arm, as close up to the angle as you can. This will make the end of the short arm stand out in a horizontal plane against the side of the body board.
At the end of the short arm, with its centre exactly 3 inches from the inner face of the long arm, drill or punch a hole of the right size to receive the threaded end of the leg iron, but no larger. (For our Ovis montana ram it should be half an inch in diameter.) File off the sharp corners of this end.
[a]Fig. 31.]—An Iron Square.
At a point about 1-1/4 inch from the inner angle of the square, and in the long arm, drill a hole about 7/16 or 1/2 an inch in diameter, for a stout bolt to pass through. Between that and the end of the long arm, drill (or punch) two screw-holes, and countersink them. That is all there is to the making of the square, and the accompanying cut (Fig. 31) accurately represents it. Each pair of squares is put on with a single square-headed bolt, the length of which varies according to the thickness of the body board. For our mountain ram, the bolts should be 3/8 of an inch in diameter, and about 2-1/2 inches long.
It is useless and unnecessary for me to attempt to describe the different sizes of squares necessary for animals of various sizes, for circumstances must be the instructor in that. I will remark, however, that for a large bison or moose, where the finished specimen will weigh perhaps 600 or 700 pounds, and the strain on the irons is very considerable, I have found it necessary to make squares of flat iron 3/8 or 7/16 of an inch thick by 1-3/4 inch wide.