OCIENCE NOTES AND NEWS.

Manawatu Herald, Volume XXXIX, Issue 1674, 13 February 1917, Page 4

OCIENCE NOTES AND NEWS.

COLOURS AND HEAT,

In an attempt to illustrate graphically the relative values for summer wear of different colours in dress materials, an interesting experiment was recently conducted. Four strips of cloth, made of the same material and weight, but of different colours, were placed on a cake of ice and exposed to the sun. The fabrics were white, yellow, red, and black. The result showed in a striking way how white reflects the sun’s rays while black absorbs them.

The ice covered by the piece of white cloth was not melted to any appreciable degree during the test; that under the yellow strip was slightly depressed; a deep cut was formed beneath the red cloth, and a groove approximately twice as deep as that covered by the latter was melted under the black fabric. THE PHONOGRAPH ALOFT.

When the military aeroplane is scouting, it usually carries two men. One is the pilot, who runs and steers the craft; the other is the observer, who marks the placing of the hostile troops, the position of their guns, the movement of trains, etc. The observer also makes many sketches of the ground over which he is flying—work that often interferes with his writing notes and memoranda. In certain conditions of flight, too, it is often hard for him to use a pencil and paper. To obviate that difficulty, the military aeroplane now frequently carries a phonograph, with a speaking tube running to the mouth of the observer, so that by talking into the machine at any time during the flight he can record his observations and still have his hands free for his fieldglass or his sketching pencil. RAINDROPS. Raindrops do not always have the same size or weight, and this is primarily due to the fact that they are not formed like the drops of water that fall from a wet cloth or the spout of a pitcher, or the drops that rush out of the small holes in the garden sprinkler. In all these latter cases a solid stream of water is broken up into drops; but the raindrops are formed in the cloud by the accumulation of minute atoms of water drawn together into one drop, and sometimes by the melting of a large snowflake or a solid icy hailstone. When a drop is thus formed in the clouds, it begins to fall, no matter whether it be large or small, and observers in balloons state that all sizes of drops are to be found within the clouds themselves, from the finest fog and drizzling mist up to the heavy rain. It is commonly said that the bigger drops fall taster than the smaller ones, and overtake them and grow bigger. FINDING STEEL FLAWS. Considerable success in detecting concealed flaws in steel intended for marine engines and driving parts has been attained at the engineering experiment station of the United States Naval Academy by photomicroscopic examination of the finished products. The method consists of photographing through a microscope large objects, as for instance a. propeller shaft, instead of confining such inspection to the small specimens taken from forged or cast parts' during the course of manufacture. In order to examine such things as a full-sized shaft, connecting-rod, or gun-jacket, a portable photomicroscopic apparatus is clamped in various positions to the object under inspection so that a fairly comprehensive photographic exploration is made. From the results so far attained it is believed that it is possible in this way to detect with reasonable certainty dangerous flaws or internal cracks in important parts upon which the safety of a vessel depends.