Miscellany.

Southern Cross, Volume 3, Issue 3, 20 April 1895, Page 3

Miscellany.

CONCERNING COMETS. £>&tgnV' Sir Robert Ball, lecturing recently on comets,-- said : There ' was on© comet which they were always sure of coming back again, and that was Halle’s comet,, which was the one due in 1910. Tt turned up e'very Seventy-' five years, and had been noticed for 2000 years. Its last appearance was in 1835. In the Middle Ages it caused terrible alarm. The Pope on one occasion ordered all the church bells to be set ringing, whereupon the comet took the hint and soon appeared. Much' 'amusement. ,w.as caused by a sketch from the Bayeux Tapestry, which represents a party of awe-stricken star-gazers pointing to Halle’s comet in 1066. The lecturer next spoke of Encke’s comet—which had been called a Manx comet, because it was tailless—and of the valuable -information which had re-, cently been obtained from it in regard to the mass of the planet Mercury. Encke turned up every three years. Once it was an hour or two late, and appeared a little upset and disordered. The astronomers immediately questioned it about its conduct, and Encke had to explain that just after leaving the sun it had nearly fouled the planet Mercury, and had been a good deal pulled out of its course. They were quite satisfied that the comet had declared the truth, and from the amount of disturbance that Mercury had caused they were able to calculate, the mass or quantity of matter in that planet, a piece of information that hitherto they had been unable to arrive at. As to the constituent matter of the comets, it was clearly of the flimsiest kind. Sir John Herschell was hardly exaggerating when he declared that you' could pack one of the biggest comets into a porbmateau, and carry it with ease. A comet on'ce ran into-Jupiter and all his moons, but without disturbing them in the slightest degree that was preemptible. Our earth passed through the tail of a Comet one Sunday evening (Midsummer 1 Day) in 1861, but nothing, happened,."except. a ciuntry clergyman complained that the sky was rather hazy that evening, and- he had to light two candles to read his sermon by. In conclusion Sir Robert Ball advanced reasons for disbelieving the old theory that comets dart out of ‘ infinite space ’ to pay, ah occasional visit to the sun. He contended that the evidence pointed: to the belief that comets were originated by vast spurts of glowing gaseous matter shot up out of the sun at a speed greater than 385 miles per second, and said this view was confirmed .by the discovery that the materials of which comets were composed appeared to be identical with the known constituents of the sun.