Amador Ledger-Dispatch, 24 June 1910 — SCIENTIFIC MISCELLANY [ARTICLE]

SCIENTIFIC MISCELLANY

Reported weekly for the Ledger.

A Plague from Sand Flies— A Pigment Wanted— Fiber-Reinforced RubberGetting the Burglar's Measure— A Paddle-Wheel Brake— Science Heading off Criminals- A Neglected Tuber —Fire-Glow Recording--Glass-Coated Ships— New Fireless Cooking.

Pellagra, which has given much alarm in the United States, is a great scourge in south-eastern Europe, and a serious disorder in the West Indies, Egypt and elsewhere. Among its first symptoms is usually a kind of sunburn" of face, chest and hands. This is followed by skin rash, catarrh of stomach and intestines, feverishness, lassitude and weakness, and as the trouble recurs in spring and autumn year after year, the weakness increases, and often leads lo lunacy and death. The disease has been generally attributed to eating damaged Indian corn. Believing it to be infectious, Dr J. J.Wolfe, of Durham, N.C., has been lately seeking its organism in pellagrous blood and has obtained some spherical bacteria, without certain evidence that they are the cause of the disease. He has found a similar organism in a culture from damaged Indian corn. On the other hand. Dr L. W. Sambon, a British investigator, has long doubted the accepted theory, and in a recent visit to Italy with a Pellagra investigation committee, he convinced himself definitely that Indian corn is not a cause of pellagra. The evidence tended to show that the disease is due to a parasite conveyed by the simulium reptans, a kind of sandfly breeding on stones along the streams of pellagrous countries.

• The yellow color of balloons has resulted from necessity, not chance or idle fancy. Lieut-Col. Espitallier, a French aeronaut, explains that the textile fabric of the balloon is made impermeable by a layer of caoutchouc, and that this, even when vulcanized, is rapidly disintergated by violet or ultraviolet light, so that it must be protected by a yellow pigment to absorb the harmful rays. A new yellow pigment is much wanted, however, as neither the chromate of lead used in France nor the anilin dye of Germany is satisfactory.

A process for combining pure rubber with vegetable fiber so that the latter penetrates the material in minute threads in all directions is claimed by a London tire company. The product is remarkably tough and resistant to pressure and tensile strain.

Bertillon's dynamometer, the new apparatus added to the equipment of the French police by the famous chief of the anthropometric service, is expected to interpret the marks of the burglar's jimmy, and makes it possible to show whether a forcible entrance saw made by a man, woman, child, or several persons. A strong upright steel frame has a horizontal sliding plate as a base, with a steel plate sliding in vertical grooves for the top. The spring of the top plate is connceted to a dynamometer capable of registering vertical effort up to one ton, and a smaller dynamometer records the horizontal pressure on the base plate. Tests are made by measuring the effort necessary to reproduce on a suitable board or other material the marks found on doors or furniture. Vertical or pressure effort is always greater than horizontal effort, and a lever 20 inches long gave a vertical pressure of 300 pounds simultaneously with a horizontal traction of 330 pounds. On a hard walnut plank, a strong man can develop a pressure of 1500 pounds. Point impressions are most serviceable in identifying the tool used by a burglar, and the tool indicated is employed in investigating the opening of a window, drawer, desk, etc.

The resistance of water to a paddlewheel is utilized in a novel French brake for motor cars. A bevel-wheel is loosely mounted on a shaft between the engine and the gear-box, and can be clutched to the shaft as desired. The bevel-wheel meshes with a pinion having attached a fan or paddle-wheel in a small water tank. On using the brake, the paddle is set in motion, and the resistance of the water exerts a braking effect that is .considerable at high speeds, decreasing with lower rates. '

The elecrtric automatic typewriter of the Berlin police has added .to the Btrenuousness of the burglar's profession By means of this instrument, a robbery at one station can be followed up within two or three minutes by the printing and posting up at all stations in the city and suburbs of notices describing the thieves or giving such information as may be available.

The humble ground nut is at last attracting attention as a promising food product. For ages it has been a great delicacy to children and pigs, and it is really an excellent food, of good flavor.

The new radiometer of R. H. Smith, an English physicist, is designed to

measure the radiation falling on and absorbed by a dull black rough surface. An unbroken flat surface is formed by a coil of more than 60 feet of email square copper tube, extremely thin, and the radiant energy in the form of heat raises the temperature of water flowing slowly through this tube. The absorbing surface is very large — one square foot in area. The water is kept flowing by gravity at a uniform rate during each test, and the quantity collected is accurately weighed every five minutes, thermometers graduated to one-tenth degree centigrade, or one-fifth iegree Fahrenheit, being used to determine the temperature. In testing open fires and other house heating arrangements, the only use made of the instrument so far, from three eighths to three quarters of a pound of water per minute was heated from 6 to 10 degrees P. The accuracy is very great, practically all of the heat received being collected in the water, and so sensitive is the instrument that on adding a two-inch cube of fresh coal to a large open fire a perceptible increase in the indicated radiation was noted inh one minute.

Glass- plating is the novel method by w hich two English inventors hope to prevent the fouling of ships' hulls, even in tropical waters, The glass, in sections about six inches square, is applied direct to the bare metal with a special cement of wood pulp, resin and linseed oil, and a layer of this an eighth of an inch thick not only holds the grass very firmly but compensates for the difference of expansion between the metal and the glass. Painting' is unnecessary. The glass is claimed to make it impossible for any growths to secure a hold, and it remains firmly adherent even when cracked with a hammer.

In a combination of fireless crooker and electric stove, electric current is used to give the first heating and start the cooking, and the hot food completes the process on standing. The holding dishes are of aluminum placed one on top of another, the electric stove is beneath, and a snugly-fitting insulating hood covers all. The process is claimed to be safe and effective. Little electricity is necessary, and meals can be prepared at less than the ordinary cost.