Page:Popular Science Monthly Volume 89.djvu/498

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pulls the trigger, re- leases the firinji-pin and ignites the powder by exploding the blank cartridge. When the powder is to be ignited electrically, a wire is stretched from a switch to the bait. Once the bait is touched a circuit is closed and an elec- tric spark sets off the powder.

The shutter on the camera designed by Mr. Nesbit is operated by means of the cover placed over the con- tainer holding the pow- der. This cover is attached to a chain

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��be found. The co\er is so arranged that it cannot be blown off until the powder is burning with its great- est brightness.

When the wire to the bait is pulled, the pow- der is ignited and com- mences to burn. For a small fraction of a second the cover re- mains in place while the powder burns. Then, when the powder is burning with greatest \igor and is gi\'ing off its brightest light, the cover is blown off and the shutter of the cam- era is siKipprd.

���Below, the animal attracted to the bait, which is at- tached to a trigger which releases the firingpin

which is fastened to a tree or post supporting the lamp. This is U> prevent the ex|)losion of the powder from blowing the cover so far away that it cannot

��The wiring arrangement, showing the flash occurring at the very instant the bait is touched by the animal

Sonu-times two sets lit cameras and ilash- l.iinps are used to give iwn ]>i(iures of the same animal in differ- ent positions, before and after his fright.

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