Page:Popular Science Monthly Volume 90.djvu/859

 Popular Science Monthly

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��The submarine which will accompHsh this employs essentially the usual pro- pelling and diving apparatus found in sub- marines. Its hull is different, however. Nearly the entire bottom-half of the central portion of the boat is given over to the two storage holds. These holds are water- tight, but their bottoms can be opened to the sea. A central observation chamber between the holds also opens to the sea. A large-toothed driving-wheel is mounted at the bottom of this chamber, to help drive it along the ocean bottom. Com- pressed air is turned into the observation chamber to push thewaterout,and powerful electric lights are then turned on. The opera- tor stationed outside of the glass walls of this chamber can plainly see the bottom.

When an oyster bed is reached, the storage holds are quickly opened. Sea water rushes in. Large centrifugal pumps are started. They force great streams of the water out so that equal streams of water can be sucked in. The inrushing water carries the oysters along with it. Thousands of the oysters will pile against the wire screening which lines the storage holds in front of the water exits. The submarine thus cleans up the oyster bed

����Flexible tube tovQcuum cleaner

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��A Flashlight Advertisement on the Cashier's Register

A FLASHLIGHT change holder makes an attractive and useful decoration for showcases or for use in connection with the cashier's register. When the change is depos- ited .in the holder by the cashier, the coin forms a contact, causing a sign to flash in to view. The adver- tisement may be a colored photograph, a drawing, a slogan, or any other thing desired. It comes to the buyer's attention in such a manner that he is bound to notice it, and generally when he is in an agreeable frame of mind.

���When the coin is deposited an electrical contact is made and the sign is flashed into view

��The spiral spray creates the vacuum which sucks up the dust

Attach This Hose to Your

Hydrant to Run Your

Vacuum Cleaner

VACUUM cleaner has been invented by Beecher W. Junk of Toledo, Ohio, which can be operated wherever there is a hydrant in your house. A pipe of the right diameter is screwed into the hydrant's mouth and runs down to the bottom of the sink. A spiral nozzle fits the pipe just below the mouth of the hydrant. An angu- lar pipe opens into the vertical pipe immediately below the nozzle and slopes up to connect with a rubber hose on the guiding rod.

To clean the room, you turn on the water and guide the rod over the carpet. After traversing the spiral nozzle, the water whirls around and passes the opening of the angular pipe, forcing out all the air near it. The vacuum so created starts the air flowing in the rubber hose.

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