80 



THE WORLD'S ADVANCE 



quired. The lights and bell should be 

 fastened to a wood base which is bolted 

 to the engine frame. The connections 

 for the bell and lights, together with the 

 necessary dry cells, are shown in one 

 of the accompanying drawings. 



The switches are to be screwed to a 

 board which is installed in a convenient 

 place on the grader. They should be 

 constructed in such a way that easy and 

 quick manipulation is possible. Fig. I 

 illustrates the switch. The handle can 

 be turned from hard wood stock and 

 when finished should have a length of 

 about 8 inches. Various adjustments of 

 the switch will cause different contacts 

 to be closed which will result in the bell 

 or one of the lights giving a signal. 



Fig. 2 illustrates the connecting plug, 

 which should be bolted to the frame of 

 the tractor. It comprises a long, flat, 

 wooden block, bored out lengthwise with 

 four small holes into which four spurs 

 attached to another block will fit. Brass 

 springs should be screwed upon the face 

 of the large block and bent to fit into 

 holes so that they will come in contact 

 with the four spurs. 



In signaling, the operator on the 

 grader throws the switch either to right 

 or left, according to which direction he 

 desires the tractor to turn. The switch 

 is depressed when he wants the tractor to 

 stop. 



Contributed by 



J. C. LUNDHOLM. 



Punch for Locating Dowel Holes 



The task of locating with the neces- 

 sary degree of accuracy a pair of dowel 

 holes in wood is frequently a difficult 

 one. The 

 little de- 

 vice shown 

 in the illus- 

 tration will 

 m a terially 

 aid the 

 w o r kman 

 in p e r - 

 f o r m i n g 

 t h e task, 

 and, cpn- 

 s i d e r ing 

 the ease 

 with which 

 the tool 



may be made, it should find a place on 

 every workbench where woodworking is 

 done. 



The punch is made up of two pieces, 

 i. e., the punch proper and the frame or 

 holder. This is desirable because the 

 construction is economical and it makes 

 the device interchangeable. The punch 

 can be removed from the frame and an- 

 other inserted in the event that a hole 



Defoi/ of Punch 



form of fare/ Used 



of a different size is desired. The reader 

 will note that the upper end of the punch 

 is fitted with a slot in order that it may 

 be quickly removed or replaced with an 

 ordinary screw driver. 



The de- 

 vice is in- 

 v a 1 u a ble 

 for mark- 

 i n g off 

 dowel 

 holes in 

 the edges 

 of boards 

 used for 

 table tops 

 and in oth- 

 e r places 

 where it is 

 e s s e ntial 



Defo// of frame 

 *ethod of Hurting Dowel rto/es 

 Locating Punch for Dowe/ flo/ej 



that accu- 

 rate work be done. By fitting a set of 

 these punches to a board that has been 

 drilled for the dowels, and bringing up 

 the adjacent board, all of the holes in the 

 second board can be marked off together 

 and in exactly the correct relation to 

 each other. There are other uses to 

 which this suggestion may be put. 

 Contributed by 



JOHN LEAFSTROM. 



