[Illustration:  Wiring Diagram]

** How to Tighten a Curtain-Roller Spring [79]

A common table fork can be used to hold the little projection on the end of a curtain roller for tightening the spring.  Hold the fork firmly with one hand while turning the roller with the other.  Do not let go of the fork until the little catches are set in position to prevent the spring from turning, or else the fork may be thrown off with dangerous force.

** Alarm Clock Chicken Feeder [79]

An automatic poultry feeder, which will discharge the necessary amount of corn or other feed at any desired time, may be made by using an alarm clock as shown in the sketch.  A small wire trigger rests on the winding key and supports the swinging bottom of the food hopper by means of a piece of string which connects the two.  When the alarm goes off the trigger drops and allows the door to open, thus discharging the contents of the hopper.

After the device has been in operation for some time the hens will run to the feeder whenever the. bell rings.  —­Contributed by Dr. H. A. Dobson, Washington, D. C.

[Illustration:  Will Open or Close Circuit as Desired]

** Homemade Disk-Record Cabinet [79]

Select some boards that have a nice grain and about 1 in. thick and 12-in. wide.  Cut the end pieces each 36-in. long and trim down the edges so as to make them 11-3/8 in. wide.  The top board is made 28-in. long and full 12-in. wide.  The three shelves are cut 25-in. long and the edges trimmed so they will be 11-3/8 in. wide.  The distance between the bottom of the top board and the top of the first shelf should be 3 in.  Two drawers are fitted in this space, as shown in Fig. 1.  A series of grooves are cut 1/4 in. wide,

[Illustration:  Cabinet Holding 32 Records]

1/4 in. deep and 3/4 in. apart on one side of the top and bottom shelves, as shown in Fig. 2, and on both sides of the middle shelf.  The shelves should be spaced 9-5/8 in. for 10-in. records and 5-5/8 in. for 6-in. records.  A neat scroll design is cut from a board 25 in. long to fill up and finish the space below the bottom shelf.  —­Contributed by H. E. Mangold, Compton, Cal.

** A Battery Rheostat [80]

In a board 7 in. long and 5 in. wide bore holes about 1/4 in. apart, in a semicircle 2 in. from the bottom, and cut notches in top end to correspond with the holes.  From a piece of brass a switch, C, is cut with a knob soldered on at the end.  Nails for stops are placed at DD.  Two binding-posts are placed in board at A and B. With about 9 ft. of fine iron wire attach one end to the bottom of post A and run through first hole and over in first notch to back of board and then through second hole and over second notch and so on until E is reached, where the other end of wire is fastened.  Connect switch to post B.  —­Contributed by Edmund Kuhn, Jr., East Orange, N. J.

[Illustration:  Battery Rheostat]