STEAM TOPS.
Too Long; Didn't Read
A very interesting and novel application of the steam turbine principle is to substitute for a wheel running in fixed bearings a “free” wheel pivoted on a vertical spindle, the point of which takes the weight, so that the turbine becomes a top which can be kept spinning as long as the steam supply lasts.
These toys, for such they must be considered, are very easy to make, and are “warranted to give satisfaction” if the following instructions are carried out.
A Small Top.—Fig. 74 shows a small specimen, which is of the self-contained order, the boiler serving as support for the top.
[Illustration: FIG. 74.-Simplest form of steam top.] [1]
[Footnote 1: Spirit lamp shown for heating boiler.]
For the boiler use a piece of brass tubing 4 inches or so in diameter and 3 inches long. (The case of an old brass “drum” clock, which may be bought for a few pence at a watchmaker’s, serves very well if the small screw holes are soldered over.) The ends should be of brass or zinc, the one which will be uppermost being at least 1/16 inch thick. If you do not possess a lathe, lay the tube on the sheet metal, and with a very sharp steel point scratch round the angle between tube and plate on the inside. Cut out with cold chisel or shears to within 1/16 inch of the mark, and finish off carefully—testing by the tube now and then—to the mark. Make a dent with a centre punch in the centre of the top plate for the top to spin in.