With an old coffee can, or similar tin receptacle, and a piece of a broom handle, 2¹⁄₂ or 3 ft. long, it is easy to make a corn popper that is preferable in many ways to a wire one. Take a strip of wood a little shorter than the height of the can to be used, and after boring two holes in it to prevent its splitting, nail it to the end of the handle. The latter is then fastened to the side of the can with two wire staples, as shown. Holes are made in the can top to admit air to the corn while it is popping.—James Crouse, Dixon, Ky.
An Easily Constructed Ball-Bearing Anemometer
By THOMAS A. REYNOLDS
An anemometer is an instrument which measures the velocity of the wind. The anemometers used by the weather bureau consist of four hemispherical cups mounted on the ends of two horizontal rods which cross at right angles and are supported on a freely turning vertical axle. Since the concave sides of the cups offer more resistance to the wind than do the convex sides the device is caused to revolve at a speed which is proportional, approximately, to that of the wind. The axle, to which the rotary motion is transmitted from the cups, is connected to a dial mounted at the foot of the supporting column. This dial records automatically the rotations. The reproduction of such a registering mechanism would be rather complicated. Hence, in the arrangement to be described none will be employed. Therefore, one of these improvised anemometers, when mounted on a high building, will indicate by the changing rapidity of its revolutions only the comparative, not the real, velocity of the wind.
This Anemometer is Made from Galvanized Sheet Iron, a Bicycle Hub, and a Few Iron Straps. Practice in Observing Its Motion will Enable One to Estimate Fairly Closely the Wind’s Velocity
In constructing the instrument, straight, dished vanes will be used instead of hollow cups. The vanes operate almost as effectively and may be combined more readily into a sturdy rotating unit. A bicycle front hub is utilized to constitute a wear- and noise-proof bearing having minimum friction. Each of the four wings is formed from a piece of galvanized iron, measuring 4¹⁄₂ by 10 in., which has one end cut to a curve as shown. To each wing is fastened, with tinners’ rivets, a 4-in. length of ³⁄₄ by ¹⁄₁₆-in. strap iron. Form each of the strips into a trough-shaped vane, measuring 2¹⁄₄ in. from edge to edge—this being the distance between the spoke flanges of a bicycle hub. Some cylindrical object of suitable diameter will serve as a form for bending. Place the ends of the support strips between the spoke flanges and rivet them securely. The rivets pass through the spoke holes. Some trying out may be required to insure a symmetrical arrangement of the parts. Solder the curved end of each wing to the inner surface of the adjacent wing. Place a tin cap—a salve-box lid will do—under the upper locknut on the hub to exclude rain from the bearing.
The supporting upright may be a heavy wooden rod, or a piece of iron pipe. A yoke of 1 by ¹⁄₈-in. strap iron, held to the top of the upright with screws, is provided for the attachment of the hub. The locknut on the hub clamps it to the yoke. Apply a coat of metal paint to the iron parts which are exposed. Mount the device sufficiently high to give the wind free access to it from all directions. The curve at one end of each wing is an irregular one. Hence, its accurate construction involves a knowledge of sheet-metal pattern drawing. However, if it is made of a form similar to that shown it will fit sufficiently well to permit a good soldered joint.
¶Boards exposed to the weather should be laid with the heart side down, as determined by examining the end grain.
Fig. 2