Page:Popular Science Monthly Volume 88.djvu/473

 Popular Science Monthly

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��wide. By enlarging the body as regards length and width, from three to four passengers could be carried, provided the body was strengthened accordingly, the occupants sitting in the same man- ner as they would on a double runner sled. This requires a few inches addi- tional width to the body.

Fig. 2 shows a different motor and seating arrangement from that sub- mitted in Fig. 1. On the machine in

��Fig. 1. Side view of small

racer, showing steering gear

and brake action

���Fig. 2 the motor is placed in front, driv- ing the propeller, through a long shaft, at the rear. This shaft runs between the passengers along the middle of the vehicle, as can be seen from the top view plan in Fig. 2. Note that the shaft is enclosed where it passes through the cockpit. From this sketch it is apparent that sociable seating is employed. This requires a wider body which tends also to cut down the speed, but at the same time allows of several passengers being carried, and the use of more power.

The body construction is practically the same in either machine illustrated in this article, but, of course, due allowance should always be made for the weight carried. A one or two passanger ma- chine may be constructed so as to weigh little over 100 pounds complete, but in all cases it is advisable to build a light frame to lay the planks on, although in the case of a small machine it is per- fectly possible to obtain sufficient strength from a body constructed of four boards of the proper shape fastened edge to QcXgQ, in which case the side boards should be fairly thick, or else have their edges re-enforced with mould- ing inside.

As has already been stated when tandem seating is utilized the motor should be situated at the rear, in which case the aerial jiropeller can be directly connected to the crank shaft of the

��motor, thus constituting the complete power transmission.

The runners for both of the models described in this article are constructed in the usual manner of wood, shod with steel or iron edges, these being formed of square rods set in the wood edgewise so as to present a sharp running edge to the ice. They are held in this posi- tion by their extremities, which are flattened and secured to the wooden runners.

Both machines can be made with only three runners, one in front by which the boat is steered, and two at the rear. The size of these rimners de- pends to some extent upon the load to be carried, but for ordinary use runners from twelve to eighteen inches long should prove entirely satisfactory. When it is the intention of the builder to carry many passengers, the spread of the rear runners should be widened considerably, or else the machine should be fitted with four runners.

The steering of the motor ice-craft here described is accomplished by means of two beveled gears and shafts as illus- trated. This fixture can be rigged up by using the gear mechanism found on an old ice cream freezer. This changes the plane of rotation as desired and

���Fig. 2. Top view of another form of racer, in which the motor is in front, and the propellor at the rear. This form of ma- chine holds two passengers

saves the cost of a regular steering mechanism. In case the former device is emjiloyed, a large steering wheel should be provided, as the ratio of the gears utilized is rather high.

Braking the speed of the aero ice-boat is accomplished by means of the lever drag brake shown in the drawing. The com])lete brake is constructed of two ])ieces of iron or soft steel riveted to- gether and forged to the shape illus- trated. The brake is held in the proper position when not in use by means of a

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