Though I have seen the same arrangement at the top, yet a better way is as follows: (Figs. [10], [11] and [12].)
Fig. 13.
Have your blacksmith make three flat pieces of iron, each six and one half inches in length, having a closed loop turned up at the end, which carries a link six inches long, as in [fig. 10]. Bolt this piece of iron near the upper corner of each of the end walls—that is, above each of the short hooks, allowing the loop in which the link hangs, and no more, to project. Get at the same time three squarely bent hooks of round iron ([fig. 11]), with a thread and nut at the long end, and the bent-up point no longer than the inner diameter of the link, lengthways, so that it will freely pass through the link. Set these hooks in those unprovided upper corners of your remaining walls that come opposite your links when the walls are set up, at such a distance that when the link is bent around the corner it will snugly fit over the hooks. In order to do this, however (and you can see what I mean by a glance at [fig. 12]), you must set your hooks so loosely that you can turn their points backwards. The link is then slipped over, and the reversion of the hook to the position shown in [fig. 12] binds the two walls cornering there as securely together as the interlocking hooks hold them at the bottom.
Fig. 14.
You will notice that I have no clamps or link at the front end near the door. There is no chance for any. Instead we trust for solidity to the outside brace, which is specially important, and to the horizontal brace which extends across from the top of the wall to the forward upright. (See [fig. 13].)