Ferris, Richard. [from old catalog] · New York, T. Nelson and sons · leaf 238
nd three-quarter feet of pure rub-ber tubing are required. It is tied together with silkso as to form a continuous ring. This is looped overtwo screw-hooks of brass, one in the rear block andthe other constituting the shaft. This looped tubingis twisted by turning the propeller backward abouttwo…
Aeronautics
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