Detail of the Parts for the Construction of the Ice Glider, or Pushmobile
The crosspiece is 30 in. long and about 8 in. wide. In the center of this piece an upright is constructed, 26 in. high. The edges of the front crosspiece are cut on a slant so that a piece nailed to its front and back edge will stand sloping toward the rear. A handle, 24 in. long, is fastened between the two uprights at the upper end. The rear part is made of a board, 8 in. wide and 40 in. long. The remaining skate is fastened in a perfectly straight position on the rear end. The skates may be attached with screws run through holes drilled in the top plates, or with straps. The front end of the rear board has a hole for a bolt to attach it to the center of the front crosspiece, so that the latter will turn to guide the glider.
A pusher is prepared from a block of wood, into which nails are driven with their ends projecting on the under side. The block is strapped to one shoe, as shown.
The Block of Wood with Projecting Nails to Fasten on the Shoe That Does the Pushing
The glider is used in the same manner as a pushmobile.
The pusher can be made in another way by using sole leather instead of the block. Small slots are cut in the sides for the straps. Nails are driven through the leather so that the points project. Either kind of pusher is especially adapted for the pushmobile to prevent wear on the shoe.
Prony Brake for Testing Small Motors
The ordinary prony brake is not, as a rule, sensitive enough to make an accurate test on small motors, such as those used in driving sewing machines, washing machines, vacuum cleaners, etc. The arrangement shown in the accompanying sketch has been used for this purpose with good results and was very accurate. The operation of the brake is exceedingly simple.
