VOLCANIC GLASS DUST.

Hawera Star, Volume XLVIII, 10 November 1924, Page 8

VOLCANIC GLASS DUST.

EFFECT ON CLIMATE. American scientists are using a newlyinvented instrument to collect dust particles at high levels which are examined under the miscrope with great care (says the American Weekly). Among them are found numerous particles of ' glass—tiny beads / which,. when es amined under a microscope, are very pretty to look at. Mostly, they are supposed to be of terrestrial origin, de- < rived from volcanic explosions,, .but it is strongly suspected that many of them are ‘‘cosmic dust 5 ’ from outer space. Whenever there is a great vol- - canie explosion, immense quantities of rock dust are thrown up into the higher levels of the atmosphere, where it floats • about for a long time. The tremendous heat, melting the silica in the material thus discharged converts iYinto glass. Volcanoes commonly manufacture glass on a wholesale scale by melting quartz rocks just as we do. In Utah, Idaho, and other parts of the Wfest, may be seen .huge cliffs, wholly composed of glass. The Indians of those regions in former days made razors out of it. Krakatoa, a mountainous island between Java and Sumarta, blew up in 1883, and for three year's afterwards' there were brilliantly red sun-: '.sets all over the world, due to clouds of glass dust held in suspension far up' in the heavens. . A like phenomenon was observed for many months after the explosion of Mount Katmai, on the Alaskan Peninsula, in 1912.. Such volcanic dust obstructs the passage of the solar rays through our atmosphere —for which reason, the explosions of Martinique and of Katmai were followed in each case by exceptionally cold years; The sun is always surrounded by a vast cloud of what is, in effect, volcanic dust, variation in the quantity of which has largely to do' with the fact that the amount of heat delivered to the earth by that luminary is . sometimes 10 per cent, more than others;