TEE WORLD'S ADVANCE 



89 



should be fastened to one end of 

 the spring, the other end being 

 attached to the car frame or lamp 

 bracket. The crank handle is 

 placed in the ring and allowed 

 to drop to a natural position, 

 where it will stay until used 

 again. This arrangement affords 

 a better means of holding a crank 

 than the usual leather strap. 



To avoid the trying experience 

 of picking screws out of the drip 

 pan by hand, an implement is 

 suggested which may be con- 

 structed as follows: Break a 

 piece about an inch long from an 

 ordinary horseshoe magnet and 

 fasten it to a rod 18 inches long. 

 Iron screws which fall into the 

 drip pan can be restored very 

 easily with the aid of this 

 magnet. 



Contributed by 



F. P. DICKOVER. 



To Remove a Broken Machine Screw 



A broken set screw can be removed 

 with a small square chisel which has 

 been sharpened to a point at one end. A 

 small hole should be drilled a short dis- 

 tance into the broken screw, the chisel 

 point inserted and the blunt end struck 

 a sharp blow with a hammer. By means 

 of a wrench clamped to the chisel the 

 screw may be turned and removed with 

 little difficulty. 



Contributed by E. E. DICKSON. 



Drawing an Elipse with a Shadow 



A perfect elipse can be drawn on 

 paper by mounting an iron ring on a 

 stand between an electric lamp and a 

 vertical drawing board. A shadow will 

 be cast on the board from the ring, and 

 will assume various forms of elipses as 

 the ring is turned. The size of the 

 elipse may be varied by moving the 

 circle nearer to or farther from the lamp. 



Contributed by JAS. MC!NTYRE. 



Acid Ink Eraser 



An attempt to erase ink with an ordi- 

 nary ink eraser or a knife usually results 

 in an unsightly blotch. Acid or chemical 

 ink erasers have a decided advantage, 

 although they are usually rather expen- 

 sive. A good acid ink eraser, 

 however, can be made quite 

 cheaply. 



Into a liter of distilled water 

 dissolve no grams of chloride 

 of lime and allow the solution 

 to stand for 24 hours. Strain 

 through a cotton cloth and add 

 10 parts of acetic acid to each 

 25 parts of solution. 



Apply the eradicator with the 

 reversed end of a pen holder 

 and absorb the surplus with a 

 blotter when the ink has en- 

 tirely disappeared. 

 Contributed by 



W. S. ZEHRUNG. 



