Monday, 1 February 2021

Liverpool Astronomical Society 1884

 Liverpool Astronomical Society 1884

Liverpool Mercury Wednesday 25th June 1884

The fifth meeting of this society during the present session was held at the association hall, on Monday evening, the Rev. T. E. Espin, B.A, FRAS in the chair. Mr. Isaac Roberts, FRAS, gave a description of his recent experience in photographing the stars and nebulae. The method he had- adopted was to fix two, and sometimes three, cameras upon the declination axis of his large telescope, and to take simultaneous photographs of a star-group or nebula, using similar plates, and allowing the same exposure to each.- The Chairman said the results obtained by Mr. Roberts were most valuable, and the society was much indebted to him. The observatory at West Kirby had lately been furnished with one of Grubb's large stellar cameras, fitted with clock motion and equatorialy mounted, and he hoped shortly to be able to give a satisfactory account of its performance.

Mr. S. B Peal advanced a new theory of lunar formation. He had been struck by the inadequate explanations at present in vogue and, after a critical examination of the lunar surface, was led to believe that the rings and angular formations were caused by condensed vapour, snow of a sort, though not necessarily the same as ours. In the case of the Himalsyas, the snow lies for ages unchanged, even under a vertical tropical sun. The objection that the snow would appear dazzling white was met with the suggestion that meteoric dust falls on our polar regions, even in such a quantity as to be visible to the eye. and our snow is re-newed, whilst the lunar snow would be permanent.

Captain W Noble, FRAS, held that this theory entirely failed to account for the physical aspect of the moon. Every one who had looked at the moon through a telescope would be familiar with the light green hue of the sea of serenity, and the somewhat bluer green of the sea of humours. Other districts also exhibited a variety of colours, so that the amount of meteoric dust necessary to produce those effects would have thrown the recent efforts of Krakatoa wholly into the shade. Moreover, it would be remembered that the photo- metric determination of the moon's light shows that her surface is nearer black than white. Nor did Mr. Peal seem. to consider the recent re- searches of Lord Rosse, who had calculated that the moon roust at tines be heated to something like 500 degrees Fahr., a condition that certainly did not obtain on the Himalayas.

Mr. J. IV. Appleton, F. R A.S., said the limit of the terrestrial snow-line depended more upon temperature than height, and varied, with the latitude, from the level of the sea to 16,000 feet above it.

Mr.W. H. Davies, FRAS remarked that Captain Noble’s argument, based on the determination of the moon's light, seemed to have been anticipated by the theory of meteoric dust. But it struck him that this was getting out of one difficulty only to get into another; for if the sun's rays were not reflected , they must be absorbed, and then what became of the snow?

P'apers were also contributed by Mr. W. H. Gage, F.R A.S., on Variable Stars; by Mr. H. Corder, on " Meteors ;" and by Mr. Stanley Williams, on " The Comet Pons.-' Dr. William Huggins, FRS and the Rev. S. J. Perry, F.R.S. (Stoney- burst), were elected associates, and nine new members were elected. Several photographs of stars and nebula were exhibited, and a simple equatorial mounting for small telescopes was described.

No comments:

Post a comment