Popular Science Monthly 



685 



A Coffee Percolator That Never 

 Runs Dry 



A PARTICULARLY successful con- 

 trivance for attracting attention to 

 his store window was recenth" dexised by 

 a Chicago merchant. 



A coffee percolator was suspended in 

 the middle of the window on a wire, tilted 

 at a considerable angle. From its spout 

 issued a dark brown stream of palatable- 

 looking coffee, which flowed into a cup 

 conveniently placed beneath. The 



curious part about the arrangement was 

 that the supply of coffee seemed in- 

 exhaustible. The percolator poured 

 into the cup hour after hour, day 

 after day without seeming to 

 diminish the supply. How so 

 much coffee could be con- 

 tained in the small pot was a 

 mystery. The vessel hung on 

 the wire entirely free from 

 contact with other objects — 

 seemingly an inexhaustible 

 fount. Another strange thing 

 was that no matter how much 

 coffee was poured into the cup 

 below, the liquid never over- 

 flowed, nor rose above a certain 

 height. 



The secret was this. Up the center of the 

 down-pouring' stream from the percolator 

 spout ran a small copper tube, its upper end 

 terminating well within the spout. The 

 coffee was conducted from a concealed tank, 

 up through the tube into the percolator and 

 out again, this time on the outside of the 

 conducting tube — the flow being sufficient 

 to completely cover the 

 pipe. The natural deep 

 brown of the coffee 

 harmonized with the 

 coppery hue of the tube. 

 The cup never ran over 

 for the simple reason 

 that a drain pipe at the 

 bottom took care of the 

 constant inflow. The 

 cup into which the per- 

 colator poured stood 

 upon a small tabouret 

 whose legs were of suffi- 

 cient width to conceal 

 the two tubes — the sup- 

 ply pipe and the drain. 

 An ordinary steel drill 

 was used to bore the 

 holes in the bottom of 

 the cup and saucer. 



The coffee comes from a supply tank 

 in a continuous stream, and flows out of 

 the bottom of the cup through a drain-pipe 



The mouth - breathing ap- 

 paratus through which fresh 

 air is suppUed to a diver 



Pumping Air to a Diver 

 Through a Bicycle Pump 



A SIMPLE plan which 

 boatmen along the Seine 

 use to supply air to divers, in- 

 volves the use of a bicycle pump, 

 the hose of which is connected with a 

 breathing device fastened over the diver's 

 mouth. The person on shore pumps the 

 air at a given rate and the diver is enabled 

 to stay under water as long as is necessary 

 to complete his work, without returning to 

 the surface on account of a diminishing air- 

 supply. 



The device is composed of an elastic 

 band which fastens 

 around the head, hold- 

 ing the tube in place 

 and making a water- 

 tight covering over the 

 mouth. The tube ter- 

 minates in a mouth- 

 piece which is held be- 

 tween the teeth. This 

 mouthpiece is a minia- 

 ture air reservoir, 

 through which the in- 

 coming fresh air is 

 passed to the air pas- 

 sages at the back of the 

 throat, and the used air 

 is expelled through an 

 exit pipe. A pair of 

 pinchers are clasped 

 over the nostrils to pre- 

 vent nose breathing. 



