ASTRONOMICAL SOCIETY

Otago Daily Times, Issue 24407, 19 September 1940, Page 5

ASTRONOMICAL SOCIETY

ANNUAL MEETING ADDRESS BY MR G. S. SMITH The annual meeting of the Astronomical Section of the Otago branch of the Royal Society Of New Zealand; was held on Tuesday evening. Mr W. D. Andefson presiding. Moving the adoption of the annual leport and statement of accounts, the chairman reviewed th work of the year and remarked that owing to the absence ol planets from the evening skies throughout the year, and ho doubt also to the distractions of the war. the attendances at the observatory on the public nights had not been quite so good as usual. Nevei--theless, a full programme of work had been carried out and altogether it could be claimed, the chairman said, that the society was functioning well and filling a useful place in the life of the community. He expressed the hope that favourable overhead conditions would prevail on November 12, when a transit of Mercury was due to occur. Those wishing to view this phenomena would have an opportunity of doing so by visiting the observatory In the morning of that day. The election of officers resulted as follows: Chairman. Mr John C. B;gg; actingchairman. Mr W. D. Anderson: honorary secretary and director of observatory, Mr W. H. B. Hobbs: honorary treasurer, Mr W. D. Anderson; committee—Dr C. M Focken, Professor R. J. T. Bell, Messrs W. A. Drew, E. G. McGeorge, H. Gardner, G. Coullng, and G. S. Smith. Transit of Mercury At the conclusion of the annual meeting a very interesting address. Illustrated with views projected by the Epidiascope and the Planetarium, was delivered by Mr G. S. Smith. Only two planets, Mr Smith said, could come between the earth and the sun and so, appear on the sun’s face. They were Mercury and Venus, whose orbits lay wholly between the orbit of the earth and the sun. The distances from the sun of the orbits of these three planets were: Mercury 38,000.000 miles, Venus 67,200,000 miles, and the earth 92,900,000 miles Mercury revolved round the sun in 63 days, Venus in 225 days, and the earth in 365 days. A transit could be taken only when the earth, one of the planets, and the sun were in a straight line. The phenomenon of transits was a rare one, and the next transit of Venus would not take place until the year 2004. "To observe the transit of Mercury across the face of the sun, a telescope is essential.” Mr Smith said. “ Mercury will pass across the face of the sun from about 8.15 a.m. till about 1.15 p.m, on November 12, and will appear In a telescope as a tiny black point. The best method for observing eclipses, sunspots, and transits is to project the Image of the sun through the telescope on to a piece of white paper, preferably in a darkened room. The eye piece may be moved out of the ordinary focus to produce a good-sized image of the sun on the paper. Trial before the transit is due to take place will show the best focus for clearness of vision. Mr Smith mentioned that it was on an expedition fitted out and financed by King George 111 that Captain Cook discovered New Zealand. Cook’s voyage was to Tahiti ,to observe the transit of Venus in 1769. That was only the third time It had been actually observed, and there had been only turn since. Mr Smith detailed the history of the various transits and explained how the earth’s distance from tire sun was worked out from observations of the transits taken from various countries. At the conclusion of the address Mr Smith answered numerous questions, and, on the motion of Mr W. H. Drew, was accorded a hearty vote of thanks for his address.