Page:Popular Science Monthly Volume 89.djvu/856

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��Popular Science Monthly

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The fan spins like a great pin-wheel when the aeroplane is under way and produces the power to drive the dynamo

Making the Aeroplane Generate Its Own Power for Wireless

TELF-:GRAPHINC; from aeroplanes by wireless has become an ordinary oc- currence in the European war zone. But some trouble has been encountered in securing the power to send the messages. The wireless transmitter on an aero- plane must, of necessity, be very light and compact, liut it does not require a great amount of power.

Batteries are not regarded fa\orably for the purpose because it is practically impossible to send messages far with- out increasing the number and size of the batteries until their weight becomes prohibitive. A few of light weight will not prod sufficient voltage.

By far the best plan tcstci thus far involves the use of a small dynamo which generates directly the al- ternating current neces- sary. It is arranged to be dri\'en through gears or by a belt from the main gasoline motor of the aeroplane. Or it may I)e dri\eii indirectl>' iiy means of an "aerofan" as shown in the illustra- lioii. 'l"his fan spins like a great pin-wheel wlien the aeroplane is uncler way, producing power to drive the dvnaino.

���Tlie novel device for dividing the profits between the owner and the lessee, and for tlic rejection of spurious coin sluns

��An Unusually Fair-Minded Slot Machine HE weighty cjuestion of the gain or loss of a\-oirdupois which is so often asked of the slot machine, may henceforth be brilliantly answered by an automatic elect rirally-operated beam- scale, which is claimed to be \ cry accurate and practically infallible in its measurements. The machine is coin-operated and possesses many novel fea- tures.

When the person to be weighed steps upon the plat- form and drops a coin into the slot, a small interior electric light is turned on and the large weight mov'es to the proper position on the bal- ance-lever. Then the small weight which measures pounds and fractions of pounds moves out to the balancing position and stops. The balancing weights are drawn along the beams by small motors which are automat icalh' cut off wlu-n the beam balances. Tin- interior light enables the I)atron to read clearly the weight indicated. The in\'cntion also embodies a novel per- centage-paying de- vice, separating the cash into two cash boxes, one intended for the profits resulting to the place of business where the machine is being operated and the other for the owner of the machine. When the owner's slot is filled, the next coin is diverted into the lessee's cash liox and in its course strikes a trig- ger whicii releases the owner's casii into its sepa- rate box.

The machine, moreover, displa\'s almost human in- telligence in the discrimi- n. it ion which it makes be- tween the genuine coin of the realm and counterfeits or slugs, ni\ariabl\- handing back to the customer an\- substitution.

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