The receptacle A is partly filled with alcohol, and the heating lamp lit. The heat will turn the alcohol into gas and cause a pressure, driving it through the tube B, so that it is ignited by the flame from D. The flame will have a fine point with sufficient heat to melt glass.—Contributed by W. R. Sears, St. Paul, Minn.
Homemade Steam-Turbine Engine
Select a tomato can, or any can in which vegetables or fruit is sold, and carefully unsolder the small cap on the end when removing the contents. When the can is empty, clean it well and solder the cap in place again. Procure a strip of brass, bend it as shown at A and solder it to the can top in the center. Cut a piece of about No. 14 gauge wire, the length equal to the opening between the uprights of the U-shaped piece of brass, with about 1/2 in. added for a small pulley wheel. The uprights are punched or drilled at their upper ends to admit the wire which is then adjusted in place.
The Boiler is Made of a Fruit or Vegetable Can and the Turbine of Thin Metal Strips
Two strips of tin are cut to fit in between the standards and are notched in the center, as shown at B, and slightly bent to fit over the wire shaft. These are soldered to the wire between the uprights. A small hole is punched on one side in the top of the can so that it will center the paddle of the wheel. On the opposite side of the top another larger hole is punched and tightly fitted with a wood plug. This is the opening for filling the boiler with water. The can should be filled about two-thirds full and set on a stove. The steam, coming under pressure from the small hole, strikes the paddles of the wheel with considerable force and causes it to revolve rapidly. Be careful not to set the boiler on too hot a fire.
Electric Switch for Exposing Photographic Printing Papers
The proper time to expose a printing paper under a negative should be determined and the negative marked for future printing. When this time has been found some means should be provided for making the exposure exactly the same, then the prints will be perfect and of a good tone at all times. For this purpose the instrument shown in the illustration was designed and used with entire satisfaction.
Time Switch for Operating an Electric Light in Printing Photographic Developing Papers