esh together. Fit right and left
hand leading screws to the hollow shaft of the second spur wheel, and
drill a hole through them as well as through the hollow shaft to receive
the fastening pin. Now remove the longitudinal feed screw of the slide
rest and attach to one side of the carriage an adjustable socket for
receiving nuts filled to the leading screws. The number of leading
screws required will depend of course on the variety of threads it is
desired to cut unless a change of gear is provided. 2. A writer in a
foreign journal claims to make slides, or V-shaped pieces for slide
rests, eccentric chucks, etc., on his lathe. Is any such process known
here, or any process within the capabilities of an amateur mechanic by
which the planing machine can be dispensed with? A. For small work held
between the lathe centers a milling device fitted to the slide rest in
place of the tool post will answer an excellent purpose. This device
consists of a mandrel carrying at one end the cutter and at the other
end a large pulley. This mandrel is journaled in a hinged frame
supported by a block replacing the tool post, and is adjusted as to
height by a screw passing through an arm projecting from the supporting
block. The direction of the belt is adapted to this device by means of
pulleys.

(12) J. E. B. asks: 1. What is the best turbine water wheel now in use?
A. There are several wheels in market that seem equally good. You should
examine all of them and decide from your own observation which is best.
2. What is the rule for finding the horse power of water acting through
a turbine wheel which utilizes 80 per cent of the water? A. Finding the
weight of water falling over the dam and its velocity in feet per
minute, multiply the weight in pounds by the velocity, and the result is
foot pounds, divided by 33,000, the quotient is theoretical horse power;
if your wheel gives out 80 per cent. then 80 per cent of that result is
the horse power of the wheel. 3. How can I calculate the capacity of a
belt? A. You will find an exhaustive article on the subject of belts on
pp. 101, 102, Vol. 42, Scientific American, which contains the
information you desire. 4. What machine now in use is the best, all
things considered, for the manufacture of ground wood pulp? Where are
they manufactured? A. This information can probably be obtained by
inserting an advertisement in the Business and Personal column of this
paper.

(13) C. A. R writes: Wishin