Page:Popular Science Monthly Volume 92.djvu/43

 Popular Science MoiitJibj

��27

��slight pressure that it is capable of bodily vibration by the energy of sound waves.

These two members may be employed in a circuit with a relay or other magnet whose armature is acted upon by a con- stant counter force or spring, the force of which may be regulated to move the armature beyond the operative influence of the magnet, or not, as de- sired. In the case of the toy dog, the force of the spring is such that the arma- ture is thrown be- yond the influence .;• of the magnet so that the dog must be put back into his ken- nel by hand and placed up against the magnet bar before he is again ready to be clapped out. .

With the electric train, the magnetic armature, instead of closing a relay circuit on each actuation serves to reverse it.

��Barbers may now sharpen shears with ease and sureness of result

��Sharpen Your Own Shears and Save Your Time and Temper

THE new grinding device, shown in the accompanying illustration, is de- signed to enable the barber, in a small town, to sharpen his own shears. It makes it unnecessary to send many dulled shears to a barber's supply house at a dis- tance with the resulting delay. The new device is portable and may be screwed to the edge of any table, where it is ready to be used.

The contrivance consists of a small grinding wheel mounted on a vertical shaft. A crank and worm gear supply the power. The pair of shears is held in a clamp at the top of the wheel, as shown. The clamp slides on a metal rod so that the shears may be drawn across the face of the grinding wheel as it is revolved.

���A Horn of Natural Rock. It Can Be Heard Six Miles

KING ALFRED'S Horn" is the name applied to a great shapeless block of stone in the Vale of Berks, England. It is pierced with a number of holes. By applying his mouth to it and blowing as in- to a horn, the practiced per- former can produce a weird, boom- ing sound, said to be audible for a distance of six miles. The story goes that King Al- fred used this natural horn to summon his forces for a great battle, fought in the immediate neighborhood.

���Trunks land on rubber local man makes the

��The Trunk-Smasher Is Foiled at Last by the Rubber Mat

NO matter how strong and well built a trunk may be, it will not long sur- vive if the average baggageman gets a chance to "strafe" it. A Los Angeles man would get around this by providing

rubber mats ^ for trunks to land on.

According to his plan, the mats- may readily be made of heavy garden or other hose held together by a pair of rods. Using these mats, the bag- gageman may handle trunks with his usud roughness without injur- ing them.

��mats in Los Angeles. A mats of old garden hose

�� �