Popular Science Monthly 



843 



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 



A 



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. 



