Popular science monthly . nute strandsor wires stretched across the window,several of which were severed when theglass was broken, setting into action amechanism which released the curtain. The wires, stretched tight and an-chored at their lower end to a rigidframe and at their upper end to a latch,are arranged close enough so that anobject thrown through the pane willsever one or more of them. When thisoccurs the latch is drawn downward,permitting the retaining rods to mo\e inunder forced pressure of their tensionsprings, which releases a ratchet engag-ing with a shaft round which the curtain
Popular science monthly . nute strandsor wires stretched across the window,several of which were severed when theglass was broken, setting into action amechanism which released the curtain. The wires, stretched tight and an-chored at their lower end to a rigidframe and at their upper end to a latch,are arranged close enough so that anobject thrown through the pane willsever one or more of them. When thisoccurs the latch is drawn downward,permitting the retaining rods to mo\e inunder forced pressure of their tensionsprings, which releases a ratchet engag-ing with a shaft round which the curtainis wound. The curtain falls due togra^•ity. The dc\ice has been patentetl by MaxRichtcr of Chicago, but he does notspecify any particular kiml of curtain,although he suggests that steel would bethe most effective. A simple safetya|)pliance prevents the curtain fromaccidenlly falling when the window isbeing cleaned. It is wound up on theshaft in a set position by means of asprocket wheel. The Burijflar-Proof Store-Window. Let the burglar break the g!ass ami at once a curtain of steel is released from the top of thewindow. It drops of its own weight the instant the glass is broken and one or more of thewires in back of the window are fevered. The curtain is prevented from falling when thewindow is being cleaned by a simple safety appliance. A sprocket wheel winds up the cur-tain in a set position on the shaft. The breaking of one wire will drop the curtain ?2:59 240 Popular Science Monthly Lowering a Bridge Without Blockingthe Street Traffic THE task of lowering a bridge span-ning the canal in Cincinnati with-out seriously blocking the enormousamount of traffic over the span, haspresented an in-teresting taskfor the engin-eers in large numberof car lines usethe bridge, andthere is muchvehicle and foottraffic. To over-come this diffi-culty the bridgehas been cut intwo parts andwhile one halfis being lowered and put in condition foruse, the other portion remains with car
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1872
