Popular Science Monthly 



Finding the Speed of a Worm-Gear 

 with a Bit 



IN making some experiments with a small 

 machine it became necessary to use a 

 worm-gear for a transmission. The follow- 

 ing method was used to determine the speed 

 required. The shanks 

 of several broken bits 

 were cut oflf as shown 

 at A and connected 

 with the motor by 

 means of flanges, each 

 one in turn. With the 

 use of different sizes of 



The twist of a bit drives a straight-cut 

 gear for determining reqviired speeds 



gear-wheels and bits the speed desired was 

 easily obtained. Such a gear has been 

 used on a larger machine with excellent 

 results. — E. J. Bonis. 



Measuring Through Obstacles by 

 the Triangulation Method 



IN trying to find the length of a pipe for 

 laying a line under a house or other 

 building it often happens that difficulties 

 are encountered which prevent direct 

 measurements. In such cases the following 

 method may be used: In the illustration 

 the line A-B is the one to be measured, 

 C being the obstacle that prevents direct 

 measurement. At the point D both A and 



G/ 



Finding the length of a pipe through an 

 obstacle by the method of triangulation 



B can be seen. First, sight from point A 

 over D, and beyond for a distance equal 

 to A-Dy to £. From B repeat the opera- 

 tion, making the distance D-F equal to 

 B-D. The line G when measured will be 

 found to be the same length as the line 

 A'B. — Paul I. Kennedy. 



939 



Making a Small Syringe to Clean 

 Lubricator Glasses 



THE small lubricators usually attached 

 to small stationary engines do not as a 

 rule have a drain-plug or valve at the base 

 of the feed-glass for cleaning it. This 

 makes it necessary to "blow back" through 

 the feed-nozzle to 

 empty the oil. I 

 was recently work- 

 ing on a small engine 

 having a lubricator 

 of the above type, 

 and in connection 

 with the lubricator, 

 due to poor run of 

 feed water at times, 

 the feed-glass fre- 

 quently filled with 

 sediment, making it 

 impossible to see the 

 feeding drops of oil 

 or to know whether it was working. 



The drawing shows a small emergency 

 syringe made from a lead pencil and a strip 

 of moderately heavy oiled paper. A piece 

 was cut off from the end of the pencil and 

 the lead pushed out to make the nozzle. 

 The other part of the pencil was used as a 

 plunger or piston. It was not necessary to 

 empty the oil from the lubricator in order 

 to "blow back" to clean the glass, for the 

 water and sediment were quickly drawn 

 out by simply removing the small cap nut. 

 The lubricator started as soon as the glass 

 was again filled with the small amount of 

 necessary condensation. — F. W. Bentley. 



A small syringe made 

 from a lead pencil 



A Coin Used to Close Hole of 

 Broken Oil Window 



WHILE out on a pleasure trip with my 

 motorcycle and sidecar I lost the 

 oil window nut and washer on the mechani- 

 cal oiler and could not run the motor be- 

 cause it would pump the oil out through 

 the opening and not into the motor. Being 

 30 miles from the nearest means of trans- 

 portation, I stood around waiting for an 

 automobile or farmer to pass. I put my 

 hands in my pockets and in an absent- 

 minded way pulled out a handful of change. 

 A quarter of a dollar I had seemed just the 

 size of the little oil window. I put it into 

 the place and by tapping the case with 

 the screwdriver to keep it from falling out, 

 made it fit in tightly. It served the same 

 purpose as the window for keeping the oil 

 where it belonged. — Oscar P. Becker. 



