LECTURE BY FATHER KELLY, S.J.

New Zealand Tablet, Volume I, Issue 15, 9 August 1873, Page 13

LECTURE BY FATHER KELLY, S.J.

THK TRANSIT OP TENUS. TUB Rev. Father Kelly, S.J., the celebrated lecturer, delivered a letfure at Benalla lately, taking for his subject the «• Transit of Venus." Father Kelly on coming forward was greeted with much applause. H« spoke on that event which is now creating so much interest in the icienfific world — viz., the transit of Venus. This star is one of the most glorious objects in the heavens, sometimes rising in the morning and sutnetimes in the evening, and attention was at a very early period called to its movements. Iv ancient times it was observed that the larger number of the stars appeared at all time 3to maintain their relative positions unaltered, while a few wandered about in the heavens, and hence they were called planets or wandering stars. Venus wa» one of these, and it was one of the earliest discoveries in astronomy that the star which rose in the morning and that which rose in the evening were one and the same star, viz., this planet Venus. The importance of the coining transit of Venus across the sun's disc might bo concluded from the fact that the principal governments of the world were about to fit out expeditions for the purpose of ob»erving it, and even Victoria had been called on to lend its aid in the enterprise. The object to be attained was the ascertaining of the sun's distance from the earlh ; at present it was known to be somewhere between 92,000,000 and 95,000,000 miles, and in an astronomical point of view it was highly important that it should be accurately ascertained. A transit of Venus was an event of rare occurence, because this planet moved round the sun inside the orbit of the earth, but not in tbe same plane, and hence it passed between the earth and sun at irregular intervals. There was one in 1761, another in 1769 ; the next one would occur in 1874 ; tho next, eight years latter, and there would not be another till the year 2005. In order to ascertain the distance of a he»venly body from the earth, it was necessary that its parallax should be taken ; that was to say that observations of it should be taken from distant parts of the earth's surface, and calculations made of the angle of sight. Where the distance was very great this method could not be depended on, and in the case of the sun the refraction of light was an additional source of error. But the difficulty would be overcome if observations were taken from different parts of the earth's surface of tho coming transit of Venus across the face of the sun ; the distances between the points of observation would be known, and calculations could then be made of its size and distance. In the coarse of his lecture the Rev. Father Kelly referred to other interesting astronomical facts, but we have not space to detail them. He referred to the observations of Jupiter's moons, which led to the discovery of the velocity of light j to tho number and order of the planets and to the discovery of the asteroids which were supposed to be fragments of a planet which had been disrupted by volcanic action, and finally fero'ught a most interesting lecture to a close by referring to the remarkable circumstances under which the planet t Neptune was discovered. A vote of thanks was given to the lecturer. The Rev. Father Egan then moved a vote of thanks to tbe chair j and in doing so took occasion to remark that the fact that such a large audience had attended a lecture in Benalla for the benefit of the Wangaratta hospital was a proof to him of the goodwill which the people of Benalla had towards those of Wungaratta. The chairman returned thanks, and the audience then dispersed, apparently much edified with the lecture which tbe Rev Father Kelly had delivered.