Fig. 107.—Counter-balance.
The Counter-balance is a large can filled with earth, sand, or small stones. Its weight must be equal to about three times that of the empty car. Fasten the lifting cable through holes punched in opposite sides of the can ([Fig. 107]).
Use a strong wrapping-twine for
The Lifting Cable. After tying this to the counter-balance, run it over pulley F, then over pulley E, and tie to screw-eye H in the top of the car. The cable must be of the right length so when the counter-balance has dropped to the ground the car will come just above the porch railing, as shown in [Fig. 104]. Tie
The Lowering Cable to the screw-eye screwed into the under side of the car.
As long as the weight of the car and its load remains less than half of that of the counter-balance, the counter-balance will drop and by so doing lift the car. The cable attached to the bottom must be pulled to lower the car.
Those of you boys who own a tree-hut, or intend to build one,[1] should erect an elevator similar to the one just described, for hoisting supplies to the hut.
FOOTNOTE
[1] Plans for building Tree-huts, and a Dumb-waiter for supplies, are given in Chapter XXV of "The Handy Boy."