Page:Popular Science Monthly Volume 89.djvu/454

440 ing. Details of the iron collar are shown in Fig 3. This should be made of ⅜-inch by 2-inch strap iron. It has a loop securely riveted on it, made of the same material, of such dimensions as to pass a pipe 2 inches in outside diameter, hasten this collar securely to the top of the timber with lag screws. It is also to be drilled for securing the guy cables.

The platform on the mast is 2 feet square, supported on two pieces of 2-inch by 6-inch, bolted to the timber; the details are clearly shown in Figs. 2 and 3 oi the illustration.

Note that a space 6-inch by 6-inch is provided alongside the timber and between the two supports. Standard pole steps are provided and the wood- work is given two coats of mineral red paint, and the portion to go underground is preferably tarred. The pole is then raised in the excavation beforehand provided, it should be securely guyed by three 7-strand ⅜-inch cables affiixed to the iron collar, and trued up by means of turn-buckles.

We are now ready to proceed with the erection of the pipe, which is composed of 20-foot lengths of standard 1 ¼-inch galvanized well-pipe. Black pipe of the same size, if given two coats of aluminum paint, will be found very satisfactory for the purpose.

Do not use pipe unions between joints, as they are not strong enough. A good joint may be made, as in Fig. 5, by butting the ends together and bolting through a sleeve consisting of a 2-foot length of pipe just large enough to slip on.

Erection is accomplished as follows: The top piece of pipe is inserted through the 6 by 6 opening in the platform supports, and through the loop in the iron collar, and temporarily suspended so the top is just a few inches above the collar.

Aerial pulley and rope are fastened with an eye-bolt through the end of the pipe, and the top set of three galvanised No. 12 gage iron wires secured around