Page:Popular Mechanics 1928 01.pdf/35

 leans about four inches, so that straight lines drawn upward through their centers would all meet about two and a half miles in the air. Walls 125 feet in length, vary as much as five inches at the point of greatest curvature, and even the terracotta roof is built concave to register on the eye as a straight line against the horizon. The late Prof. W. H. Goodyear, of Brooklyn institute, worked out the corrections to the building, and from his figures a scale model was first built. The separate parts were so crooked, it seemed impossible they could be hidden, but when they were all assembled the curves could only be detected by one who knew where to find them.

 

Instead of a brush, a rubber bulb and spout that produce lather for shaving, have been introduced for greater convenience and cleanliness. The lather may be applied directly from the spout to the face or squeezed into the hand and rubbed in with the fingers. Dangers of infection from unclean brushes are practically eliminated with this outfit, which is also said to save time and do away with the need of carrying an extra package of soap.



 



Amusement and healthful exercise are afforded bathers in a targetlike wheel, set at an angle on a platform near the shore. By crowding one side of the wheel, the other one is spun upward, throwing persons clinging there into the water. As the outfit is adaptable to shallow beaches. it is safe and easily rigged. The wheel itself is about twenty feet in diameter and is strongly constructed.

 To keep airplanes on an even keel and help prevent accidents, a German inventor has introduced an automatic steering-gear arrangement which is said to have proved efficient in actual tests. It consists chiefly of a rapidly rotating top to control a vertical rudder, a lead weight and a mercury pendulum of special construction to govern the other controls. The rig is said to be easily fitted to any machine and functions by causing a motor to correct the steering to compensate for any departure from the course decided upon.

¶ Approximately 20,000 kinds of beetles are found in North America.

