760 



Popular Science Motithly 



The inner tube Is made of glass stock 

 }i in. in diameter and 40 ins. long. By 

 means of a Bunsen burner with a wing 

 tip, the glass tubing can be bent into 

 the shape indicated in the illustra- 

 tion, having 10 curves, each i}i ins. 

 long. Heat the tubing until it is cherry- 

 red and then carefully bend it into the 

 proper shape, but wait till it is cool 

 before making the next curve. Care 

 should be taken to have the curves 

 uniform for fitting into the metal tube. 

 One end is now fitted into a rubber 

 stopper, which supports it in the water- 

 jacket. The other end should be smeared 

 with vaseline and inserted in the other 

 stopper, and that in turn in the outer tube. 

 Each of the short side tubes should be 

 fitted with a length of rubber tubing, 

 one being attached to the water-faucet 

 and the other to the drainage pipe. 

 Chemicals of all kinds, including mer- 

 cury, may be purified by means of this 

 apparatus. — Samuel Cohen. 



Making a Handy Power-Bench 



EVERY workshop should include a 

 power-machine like the one shown 

 in the illustration. It can be used as a 

 wood-turning lathe, for running an 

 emery-wheel, and, in fact, for many other 



This arrangement of a power-bench can be 

 made on an old sewing-machine body 



necessary operations. Procure a chain 

 and two bicycle sprocket wheels, a steel 

 rod, ranging from 3^ in. to J^ in. in diame- 

 ter and I ft. long, one side of a sewing- 

 machine stand, with the wheel and 



Lathe con- 

 struction de- 

 tails of the 

 power - bench 



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treadle, a piece of galvanized sheet iron, 

 I ft. sq., but not too thick, a thumb-bolt, 

 and a clamp from an old emery-wheel. 



Screw four supports to the top of the 

 bench, as shown in the illustration. The 

 one to the extreme left has a hole drilled 

 near the top and a short piece of tubing 

 fitted into it to receive the shaft. Screw 

 a piece of iron on the back to act as a 

 stop for the shaft. Make grooves in the 

 tops of the two middle supports and, 

 after inserting tubing, screw galvanized 

 strips over the tops to secure the shaft. 

 Drill a hole in the support represented at 

 the right. Make it a size smaller than 

 the thumb-bolt, which should be filed to 

 a point, and insert the bolt. In placing 

 these supports and drilling the holes, 

 care must be taken to keep the shaft 

 perfectly level and in a straight line with 

 the thumb-bolt. 



Make a slit in the bench exactly 

 parallel with the line of the shaft. 

 Drill a hole in the base of the right 

 support and insert a bolt to pass down 

 through the slit. Make two holes in 

 the bench at the proper place to let the 

 chains run through, and drill a hole in 

 the shaft directly above. Place the 

 part shown in Fig. i on that shown in 

 Fig. 2, and both on the part shown in 

 Fig. 3. Bolt them together, place them 

 on the shaft, pass a nail or wire through 

 the shaft, and solder it to them. At 

 the end of the shaft a number of different 

 forms of chucks may be used. 



Fasten a small board to the sewing- 

 machine wheel by means of strips as 

 shown in Fig. 4. Then attach the 

 gear. Fig. 5. A stick connecting the 

 treadle with the wheel and a support for 

 the treadle must also be adjusted before 

 the machine is complete. When finished, 

 anyone may be proud of this little power- 

 machine. — Harry B. Durlin. 



