SCIENCE NOTES.

Otago Witness, Issue 3148, 15 July 1914, Page 68

SCIENCE NOTES.

—Wonderful Figures.— Every human being on the face of the gdobe is compelled by the demands of Nature U) have two parents, four grandparents, eight groat-grandparents, 16 ancestors in the fourth generation back, 32 in the fifth, 256 in the eighth. 31,786 in the fifteenth, almost 1,050,000 in' tha twentieth, and nearly 1,073,000,000 in the thirtieth. The whole number of one’s ancestors in the fiftieth generation is 5,362,794,914,214-,046—a multitude which no man can number. . —A Wonderful Instrument. — A wonderful instrument is. the eidophone, which is used to “photograph” sounds. Certain high-pitched voices when recorded by the instr ument produced figures exactly like trees, while others gave impressions resembling flowers and foliage. Other notes still produced grotesque shapes suggestive of natural objects. Very curious was the picture produced by recording three notes of music through the apparatus. It was precisely like a tree growing beside a sheet of water. —The Wind and Sound.— A scientist has just given an interesting explanation of the action of the wind‘in preventing Jhe spread of sound • towards the direction from which the wind comes. He claims that it is not the wind that prevents sound from travelling against it, but differences in its strength. If the wind -s stronger above than below, or stronger at one side, its effect will be to tilt the sound waves in a different direction. Differences of temperature in the air also cause deflection of the waves of sound. —Microbes in the Streets. — A series of interesting tests, designed to show the great reduction in the number of microbes floating about in the atmosphere after city streets have been cleaned, has been conducted in a foreign city. Sensitised plates exposed over an uncleahed street showed so many colonies of various types of germs that it was impossible to count them. Following a superficial cleaning of the street, the plates showed about 1000 colonies. When the street had been cleaned by a squeegee machine the plates showed only about 150 colonies. —Pharaoh’s Serpents.— A cone of mercuric sulpho-cyanate, when ignited, burns with the development of a tremendous amount of ash. The cone seems to swell and writhe away like a serpent; hence the name. Any boy can make the cones at little expense. To a solution corrosive sublimate, add a few drops of ferric chloride. Dissolve potassium sulpho-cyanate in water, and slowly add this to the other solution, until, after stirring, a red colour remains. Filter through a sheet of muslin, and form the white curds into little balls or cones. Dry, and you need only touch amatch to produce Pharaoh’s Do not breathe the vapours. —A Snowfall Indoors.— A singular incident once occurred in Sweden. On a very cold, clear night, an evening party was given in a salon in Stockholm. Many persons were gathered "in a single room, and it became so warm that several women complained of feeling ill. An attempt was then made to raise a window ; but the sashes had been frozen. It was absolutely necessary that air should be admitted, so a pane of glass was smashed out. Immediately a cold current of air rushed in; and at the same instant flakes of snow were seen to fall to the floor from all parts of the room. The entrance of a frosty current into an atmosphere saturated with moisture had produced a snowfall indoors. —Evaporation and Stream Plow. — An investigation of evaporation and stream 1 flow is being carried out by Professor John F. Hayford, of the American North-western University, with the aid of a grant from the Carnegie Institution. Instead of using apparatus on a small scale to measure evaporation, Professor Hayford proposes to consider each of the Great Lakes in turn as an evaporation pan, evaluate the income, outgo (other than evaporation), and change of content of the lake, and from these data to determine the daily evaporation in its relation to meteorological conditions. Ultimately the knowledge thus acquired will be* applied to a study of the laws of stream flow in the United States. —Stability of the Solar System. — A law' connecting the distances of the planets of the solar system from the sun has been discovered by Beldt, which is in close agreement with the observed facte. The; mere existence of such a law throws light upon the stability of the solar system. A century ago Lagrange and Laplace thought they had demonstrated the invariability of the mean distances of the planets, and from that the stability of the solar system. But the mathematical series used in this investigation have been shown by Poincare to be divergent, and therefore, so far as those calculations go, the stability is uncertain. If, however, the distances of the planets' had been changed since the origin of the world by the action of the tides, their mutual attraction, etc., and if the perturbations so caused had accumulated, they would have been different for different planets, and no law connecting the distances of the planets and their satellites would have been discoverable. —A Meteorite from Zululand. — Professor Stanley describes the fall of a meteorite in the N’Kandhla district of Zululand, which took place on the Ist August, 1912. An explosion took place, which was audible over a considerable area, and _ a rapidly-moving .body was seen accompanied by a spiral trail of smoke and emitting a rumbling or crackling sound. The meteorite discovered by Professor Stanley fell within a few yards of a native woman. It weighs

nearly 381 b, and consists almost entirely of nickel-iron alloy, and is therefore classed as a siderite; it is coated with a skin of magnetic oxide exhibiting flow lines and shows numerous ‘‘thumb marks.” An analytical investigation shows the presence of iron, neckel, silicon, sulphur, carbon, phosphorus, aluminium, magnesium, platinum, and chlorine, the bulk of the meteorite being composed of iron.