Glimpses of the Unseen Universe.

Te Aroha News, Volume VI, Issue 368, 15 May 1889, Page 6

Glimpses of the Unseen Universe.

At the Literary and Philosophical Society meeting in theßoyal-institution, lately, Mr J Isaac Roberts, /.R.A SMS M F.G.S., read a paper, en tided ' Glimpoe.-? of the Unseen Universe by tlie Aid of Photography.' There was a, large audience, including members of other kindred societies in 1 Li\eipool, they .having 'been specially invited tor the evening, and the Rev. H. H. Higgins presided. The unseen uniyor.se consisted oLihe sun, planets, Gomets, stars, and nebuKc, and before illustrating Jiis lecture Mr Roberts, recapitulated the old system of astronomy by which the earth was looked uj.pn.as the centre of the universe. Sinco that~bxine Galileo had invented the telescope, and its development soon brought to light the universe befoie unseen. Reflecting telescopes v^ere then invented, and : these developed until the largest, ac Mount Hamilton, California, was now built ot the size of 36 inches in diameter and 46 feet local length. The dome or the < observatory at Mount Hamilton was 75 feet 4 inches in' diameter, aud the moveable portion weighed 89 tons., a hydraulic engine being used to regulate and chari-jce its' position. In \ddibion to these telescopes,_th'eie had been constructed during the ',pa§b Jive years a class of telescopes tor photographic application only, but' up to the last day of 1888 there Avere ' only two of theVe in existence, Mr Robeits himself owning one. The largest catalogue 'of stars was compiled by Argelander, the German astronomer ot Bonn 1 , and although ho used a telescope with only 3-inch aperture, he had charted 324,000 stars in the northern hemisphere of the sky. Several plates ot Argelander's chaits were shown, one of them having S4 stars, and thi3"' was compared with a photograph of -the «arne area by Mr Robeits's toloffcope, showing no fewer than 16,000 stars, lb svas, therefore, apparent, even on casual inspection, that the power ot registering the positions, numbers and magnitudes of the stars with accuracy »vas now in our hands, and he might further assert that it-\v«xb so from the nvsb time in the history of our race ; but ! great as the advance was in the method of charting the stars by photography,' there ' was another of as> great importance to the delineation of nebula), a class of celestial objects that had hitherto ietriaiued~a puzzle 'to all astronomeis, notwithstanding the ! closest scrutiny and study by the aid of the 'gigantic instruments that had been made !to examine them. The nebuUu had by 'spectrum analysis been proved to be gaseous ' — to consist of various gases in a hot, glowing state, or else, as Mr Loekyer had re- , cently suggested, ot solid particles of matter colliding against each other in space with such force that they weie pulverised and '.converted into a glowing gas. The uebuhe iof Orion and tho Pleiades were shown, with \ their accompaniment of intinitely numerous 'nebula;, and there were also pub upon the 'screen photographs of the nebula; of Merope, JAndiomcda, and other constellations, 'demonstrating that e\ery four squat c degrees of the sky contained on an average >16,000 stais, and the whole number could 'nob be less than 170,000,000. And who could say there -was any limit to the * numbers of the stellar universe ? What were the myriads of stars -now known to exist? They were not ! worlds, for they weie intensely hot masses like the sun, and were at distances i-o great that the nearest to us yet found amongst 'them them was 225,000 dines greater 'than the distance of the earth from the ; sun. Each one of them might be larger | than. the sun," and each might be the centie 'and governor of a system or planets or ■worlds. Bub theii\.work was to make the 'records of" the present as efficient as possible, so that their successors would be the better able to go on and tathom what were yet hidden marvels.