T' 



Gaging the Stack Draft 

 ^HE draft pressure of a stack is 

 expressed in inches of water, mean- 

 ing the amount of draft required to 

 change the difference of equilibrium of 

 two communicating columns of water, 

 measured in inches. 



The draft of the chimney can be 

 easily obtained with the use of the little 

 gage illustrated herewith. The fuel 

 consumption of a boiler can be figured 

 whether or not it is in proportion to the 

 results, etc. The illustration shows how 

 such a gage is made. A single length of 

 glass tubing with an inside diameter of 

 yi in. is bent to the required shape by 

 holding over a small flame and bending 

 very slowly when 

 hot. Fasten to a 

 board with wire 

 or brass straps. 

 Arrange a scale of 

 inches between 

 the two columns. 

 To read the 

 draft, place the 

 gage on a wall in 

 a vertical position 

 and put a little 

 water into the 

 tube so that it 

 just balances in 

 either column. 

 Connect a piece 

 of rubber tubing to the left leg and 

 seal in a small opening in the stack or 

 pipe. The draft or suction at the end 

 of the tube will cause a slight vacuum 

 in the tube and will cause the two 

 columns of water to change their level. 

 The draft may vary from % in. to 2 ins. 

 according to height of stack, temperature 

 and weather conditions. The draft 

 pressure rccjuired will depend upon the 

 kind of fuel used. Wood needs little 

 draft, about J/2 in. or e\'cn less. Bitu- 

 minous coal will require ;^<+ in. to i in. 

 and anthracite or slack will need a 

 draft of iK ins. — B. F. Dashiell. 



A Safe Way of Bending Pipes 

 ''T^HOSf^ who try to bend piping with- 

 JL out kinking by filling the pipe with 

 sand and still fail, will attain better suc- 

 cess if they pour molten lead into the 

 pipe, allow to cool and then bend. Heat 

 the pipe, allowing lead to ilow out. 



Popular Science Monthly 925 



A Toy Rubber-Elastic Winder 



A DISCARDED egg-beater may be 

 easily converted into a toy aero- 

 plane winder. Cut off the loops which 

 formed the beater part. Wire the stubs 

 together and make two wire hooks or 

 loops for fastening the rubber bands. 

 The winding will be greatly facilitated by 

 increasing the length of the crank. 



Glass tube used for 

 gaging stack draft 



An old egg-beater can be converted into a 

 good toy winder for rubber motors 



A Cheap Beam- Compass 



A WOODEN rod, such as drygoods 

 merchants use for cloth, makes a 

 good beam-compass, by attaching a 

 pencil and nail as shown in diagram. 

 The pencil is flattened on opposite 

 sides, to be gripped in the beam, and 

 the head of the nail has been filed off. 

 The rings consist of brass tubing. When 

 using ink, the ruling-pen is gripped like 

 the pencil. — Wm. Turnpenny. 



drass Ring § ' ^'D/a*^n/cM^ 



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if 5a^v Cut- 



■Z-C 



'Nail 



i^m>- 



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Diagram showing construction details of 

 beam-compass 



Removing Waterproof India 

 Ink Spots 



IT is not generally known that black 

 India ink, especially the waterproof 

 kind, may be rcmo\ed from nearly any 

 material by placing a blotter underneath 

 and pouring household ammonia over 

 the dried ink. Care should be taken 

 that the blotter does not become satu- 

 rated with the blackened ammonia. 



