Page:Popular Mechanics 1928 11.pdf/29

 

Besides the enormous quantities of timber and game they destroy, forest fires do great damage by burning natural supplies of fertilizer on the ground of wooded areas. For instance, in a pine forest, where the fall of needles insures a rich supply of nourishing materials for the plant growth of the future, this abundant fertilizer is converted into ashes by a fire, driving off the beneficial oxygen in the form of a gas that is lost to the soil and otherwise impoverishing the ground. Experts have estimated that to replace the helpful materials on one acre of pine forest, after it has been swept by a fire, it would require the addition of seventy pounds of sodium-nitrate fertilizer at a cost of about $3, and a blaze may do $10 to $15 per acre damage by this destruction alone.

 



To keep ants and other insects from entering cabinets, refrigerators and other pieces of furniture, a felt trap, saturated with kerosene or other anti-bug liquid, is attached to the casters. The felt holds a liberal supply of liquid, is easily put on and seldom needs renewal.

 

Specially processed rubber pads are being installed along the right of way of railroads in the Federal Malay states to deaden the sound of the engines and cars and to absorb unpleasant vibrations. According to reports, they have worked successfully on a trial mile of track. The pads also help protect the ties.

 



One of the chief features of the huge, ball-shaped house constructed for the "Technical City" show in Dresden, is the central court or passageway from the top to the bottom. This admits light to the hallways that radiate from the center of the building and also affords ample means for effective ventilation.

 



Clamped on the edge of the book and having a wide shade that keeps all glare from the eyes, a reading lamp is of special convenience for persons who like to read late or for use in the sick room. Since the light is directed entirely upon the pages, it does not disturb others.

¶ When frogs wink their eyes, the lids are moving upward. 