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Page:Popular Science Monthly Volume 89.djvu/764

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���Popular Science MoniltJii

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��The current of water through the vibrator is in- terrupted ten times a second with this apparatus

Making the Water from a Faucet Vi- brate Fifteen Times a Second

IF water fnjin a water-supply conduit is introduced under pressure in the outer space, or tulie, of a df)uble cyl- inder perforated with fine holes at its rear end, the water is forced to flow out through the fine holes. If a rubber membrane is stretched across the holes ii will vibrate because of the repeat'- I u[)war(l pressure of the outtlowing water and the alternate action of auction. The illustration shows a \ ibration ai)paratus embodying the principk' of an interrujiter in which the stress transmitted upon the rubber mem- brane is obtained in a simple manner. In a metal screw-ring is a rubber membrane antl below it is a rub- ber ring. When the metal ring is screwed upon the lo|) part the rub- ber membrane is stretihed acro.ss the cone, and on opening the water cock it is subjected to rapid vibra- tions. In case the vibrations of the membrane are to be transmit tetl tu a piston, the ring is removed b\' un- screwing and a fixture is usi-d instead. This consists of thi- >ame met.il ring antl in addition a pi>ton hclil inider ti-nsion by means of ,i s|)ring in the cylinder. When tlu- membrane is subjected to tin- iip- .md-down movement it pushes the |)iston upward. The piston is then

��depressed b\- the spring and again driven u[)ward by the membrane.

One peculiarity of the water-pressure in- terrupter is that in the expulsi<jn of water ten to fifteen interruptions of the current occur e\'ery second, instead of a constant Hovs'. For instance, if the out-flowing water is directed into a bottle the water ( urrent issuing jerkiK- will act more eflectiveK" in cleaning the bottle than would the ordinary flowing current nt water.

��Saving Gold and Silver on the Vacuum- Cleaner Principle

STAR 11. IXC amounts of metal ar* remo\ed from gold and silver arti- cles b\' the simple work of polishing. In the case of jewelers who do much polish- ing work during a year, the loss in gold and silver is great.

.■\ new form of polishing-machine aims to conserve the dust by means of a suction-fan mounted near the rajiiiUy re- xoK'ing brushes. The dust which ihes oft of the wheels is drawn d(jwn into a series of traps, from which it may later be removed

ind assayed for the

pure metal.

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���A suction l;in on a jeweler's polisliing macliinc draws all the gold and silver dust into a trap

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