Nozzles are made of two stopcocks having a 1/8-in. hole.  These are connected to a 3/8-in. supply pipe.  The nozzles should be set at an angle of 20 deg. with the face of the disk.  The nozzle or stopcock will give better results if the discharge end is filed parallel to the face of the disk when at an angle of 20 deg.  There should be a space of 1/16 in. between the nozzle and the blades to allow for sufficient play, Fig. 3.

The bearings are made of 1/4-in. brass and bolted to the casing, as shown, with 1/8-in. machine screws and nuts.  Two nuts should be placed on each screw.  The pulley is made by sliding a piece of steel pipe on the engine shaft and fastening it with machine screws and nuts as shown in Fig. 6.  If the shaft is square, lead should be run into the segments.

The driven shaft should have a long bearing.  The pulley on this shaft is made of pieces of wood nailed together, and its circumference cut out with a scroll saw.  Flanges are screwed to the pulley and fastened to the shaft as shown in Fig. 7.

The bearings are made of oak blocks lined with heavy tin or sheet iron for the running surface.  Motion is transmitted from the engine to the large pulley by a thin but very good leather belt.

** Homemade Telegraph Key [21]

A simple and easily constructed telegraph key may be made in the following manner:  Procure a piece of sheet brass, about 1/32 in. thick, and cut out a strip 3-1/2 in. long by 3/4 in. wide.  Bend as shown in Fig. 1 and drill a hole for the knob in one end and a hole for a screw in the other.  Procure a small wood knob and fasten it in place with a small screw.  Cut a strip of the same brass 2-3/4 in. long and 5/16 in. wide and bend as shown in Fig. 2.  Drill two holes in the feet for screws to fasten it to the base, and one hole in the top part for a machine screw, and solder a small nut on the under side of the metal over the hole.

Mount both pieces on a base 4-1/4 by 2-3/4 by 1/4 in., as in Fig. 3, and where

[Illustration:  Brass Key on a Wood Base]

the screw of the knob strikes the base when pressed down, put in a screw or brass-headed tack for a contact.  Fasten the parts down with small brass wood-screws and solder the connections beneath the base.  Binding posts from an old battery cell are used on the end of the base.  The screw on top of the arch is used to adjust the key for a long or short stroke.  —­Contributed by S. V. Cooke, Hamilton, Canada.

** Keeping Food Cool in Camps [21]

Camps and suburban homes located where ice is hard to get can be provided with a cooling arrangement herein described that will make a good substitute for the icebox.  A barrel is sunk in the ground in a shady place, allowing plenty of space about the outside to fill in with gravel.  A quantity of small stones and sand is first put in wet.  A box is placed in the hole over the top of the barrel and filled in with clay or earth well tamped.  The porous condition of the gravel drains the surplus water after a rain.