Page:Popular Science Monthly Volume 90.djvu/155

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���A SPEEDY coasting bob which is large enough to accommodate several passengers has ever been a favorite with boys wherever snow falls. The sled illustrated is an especially good design in that it is a fast, smooth runner, strong and serviceable but not too heavy to be pulled up grade. A careful study of the drawings will make it clear just how the runner is made.

The seat should be made from some light but strong wood, spruce being the first choice. Cedar, pine and hemlock are also good, the preference being in the order named. As shown in the profile sketch and in the scale drawing, the seat is 14 ft. long and 12 in. wide. It should be of selected stock, l^ in. thick, without large knots or other defects. The cross - pieces which form the foot-rests are sawed from %-in. oak, and should be 22 in. long and 3 in. wide. These cross sticks are solidly screwed

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��The profile of bob and plan of seat board with crossbars for foot-rests and tie-strips at the irends

��The rear sled is 4 ft. long and 18 in. wide. The sides are made of oak ij^ in. thick, and should be 4 ft. long and 5 in. wide. The two cross-pieces are of 1 34 in. oak, mortised into the sides and firmly fastened with 3-in. flat-headed screws. The rear rocker-blocks are shaped as shown at A and B in the drawing on the following page. These should be of 1 34 or 1 3^ in. oak of the dimensions given. Two pairs will be needed, each pair being mounted to a flat base of oak 1 3^ or 2 in. thick, 12 in. long and the width of the sled. These curved

rocker-blocks are solidly bolted to the base and the lat- ter is mortised into the top sides of the runners and screwed to them, as shown at C.

Through the curved cheeks of the rockers a hole is bored and a

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��^-in. iron bolt

��to the under side of the seat plank, 16 in. apart, as shown. On the upper side of these rests, a strip of oak i in. square is solidly screwed to the foot-rests flush with the ends. This serves to strengthen them and also adds to the appearance. At 18 in. from the end selected for the forward end of the sled, bore a hole in the center to admit the steering post, as shown.

��is run through. This "teeter bolt" construction is the very best method of fastening the rear sled, and is much superior to the usual rigid crossbar type commonly used. The illustration D is a kind of X-Ray sketch showing how the two pairs of rockers are assembled — the top pair being bolted to the under side of the seat. The runners are shod with \}/i-\x\. half- round iron, which is solidly attached to

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