Science,

Tuapeka Times, Volume XXIII, Issue 1676, 22 March 1890, Page 2 (Supplement)

Science,

Seeing The Moon's Shadow on The Earth. From Professor Todii'a artiole in the August Century entitled " How Man's Messenger Outran the Mood," we quote the following : The mton's actual motion in her oiroumterrestftal path is in the neighborhood of two thousand miles in each hour of time. This velooity is somewhat greator than that of projectiles from the best rifled guns ; but these can often be seen throughout their whole flight. Evidently the moon's motion, also, is not too great to be seen. And it oan be seen if all conditions favor the observer. Averaging a period of some decades, there are in three years two opportunities when this speataole msy be seen ; they ooour only at Buch timeß as the moon passes between the earth and the sun and causes a total solar eclipse. But even then it ib not correct to say that the moon oan be seen travelling through spaoe. At the time of such an eclipte, however, the moon's dark shadow sweeps over the earth with nearly the same velocity as the moon herself travels ; and it is this swiftly flying shadow which the alert observer may see. This imposing spectacle has frequently been beheld, but rarely unless from an elevation commanding a vast extent. Often, however, expert observers fail to see the almost tangible shadow, even when specially on the lookout for it. Not strange is it, therefore, that different eyes report so impressive a phenomenon differently. Ttt some the shadow Been in the distance resembled a dark storm upon the horizon. Some saw the shadow " visible in the air;" one speaks of its "gliding swiftly up over the heavens ;" while another likens its passage to the " lifting of a dark curtain,

Those who have taken pains to note its color do not generally call it black, but deep violet or dark brown. One describes it bs & " wall of fog," another as a " vaporous shadow," and a third Bays it was "like neither shadow nor vapor," while no less careful observers than Winneck and Lady Airy speak of the shadow as " appearing like smoke."

From their stations high above the valley ol the Ebro, over which it swept, members of the Himalaya Expedition of 1860 had exceptional opportunities for watching the approach and recession of the shadow. Many observers caw it. " When the critical moment was at hand," says one, " the darkness, sweeping over a landsoape twenty or thirty miles in extent and advancing right at me, was in the highest degree Bublime and imposing." Then and on other occasions it wbs very distinctly seen. So much for the appearanoe of the Bhadow; bat more interesting here is its speed. While observers generally remark the " frightful velocity with which it travels, President Hill of Harvard, in Illinois in 1869, found the transit of the Bhadow mucb slower and majestic and beautiful than he bad been led to expect. '' A sweeping upward and eastward of a dense violet shadow," are his words. General Abbot, ascending Mount iEtna in 1870, wrote : "At an elevation of 7,500 feet I was overtaken by tho shadow, whioh swept with great rapidity over ns, darkening the gloom to an awe-inspiring degree." The Earth's Duration. \ The present age of the earth has been placed by Sir William Thomson at 100.000.000 years, while the speculation of others have given much larger figures. M. Adolphe d' Assir, who believes such estimates to be greatly exaggerated, considers the life of the earth in three periods, whioh he terms the igneous or nebula stellar stadium, the stadium of solar illumination or of organic life, and the stadium of darkness, cold and death. The first — which began with the detachment of the terrestrial nebula from the solar, and ended in the formation of the oryetal-line crust of the globe— he calculates from physical laws to have been 500,000 years in duration. The second — comprioing the second epoch, and to close with ex tlnoticn of the son, embracing the entire cycle of geological formations — is found by geological and physical evidence as likely to have a total length of 25,000,000 years, of whioh more than half has passed. The third stadium— Btarting from the end of solar illumination, and closing in a terrible and inevitable oatastropha of the fall of the earth to the sun, and momentarily brightened by the incandescence of the earth as the moon crashes into it — will have a length that cannot be calculated until the precise rate of acceleration of the motion of the earth around the centre of attraction is known, but will probably be, at the lowest estimate 100,000,000 years or more. Upon the whole the present age of the earth appears to be about 16,000,000 years. This is but a small part of its existence, and everything leads to the belief that its total evolution through the immensity of space will exceed a million centuries. Treatment of Pneumonia by Application of Ice. Dr. Fieandt, writing in Duodecimo a Finnish medical journal,- states that be has now treated no less than 106 oases of pneumonia with ice, and with the best results. Though ten of the cases were of double pnenmonia, only three out of the whole number succumbed, notwithstanding that the epidemic was not a slight one. The method adopted was to apply over the affected lung an India-rubber bag containing ica continually for from twelve to twentyfour hoars after the crisis. In addition to the local treatment the patients were given such medicines as are usually employed, that is to Bay, opium, ipecacuanha, digitalis, brandy, &c. The method has, we may remark, received of late some attention in this country. Progress of Beet Sugar. Already more than half the world's sugar is derived from European beet root. Science, chemistry and mechanical skill have combined to transfer the habitat of a prime necessity of life from the tropios, where only it was supposed it could be produced, into the northern latitudes. Science has shown the way to prepare the soil for it, has overcome all the meohanioal problems necessary to the extraction of the sugar, made its cultivation profitable, and given employment to tens of thousands of wage-earners, and all this within the last twenty years. The future of this great industry seems almost boundlsßß in its possibilities. Egyptian Discoveries. Before the Yiotoria Institute M. Naville recently gave an account of his latest Egyptian discoveries. The lecturer gave a description of his discovery of Bubastis, j where he unearthed numerous inscriptions ! dating back to the Fourth Dynasty, among others some referring to Gheops, showing that be reigned over all Egypt, some to the invasion of the shepherds or hyksos, who, from some of their monuments found, were clearly highly cultivated, and oame from Mesopotamia. Among their statues unearthed were two of Apepi, the Pharaoh of Joseph, also inscriptions in regard to the , Pharaoh of the Exodus, and others of high interest. Engineer say a that among some things that never will be settled are the following : Whether a long ecrew-driver is better than a short one of the same family. Whether water-wheels run faster at night than they do in the day-time. Th& best way to harden atcel. Which side of'the belt should run next the pulley. The proper speed of line shafts. The light way "to lace beltp. Whether comr.rsBBion ia economical or the reverse. ' Thfl principle cf the &team injector.