Page:Popular Science Monthly Volume 88.djvu/788

 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

��/y^.4

��r/g.5

��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.

�� �