BIELA'S COMET, a comet of short period, named after its discoverer, Wilhelm von Biela (q.v.), who discovered it in 1826 and furnished such data regarding its movements as to convince the other astronomers of his day that he had a proprietary right to it. The same comet had been noticed 8 March 1772, and again in 1805. It was reckoned that the comet had passed its perihelion six times between the two periods without being detected by the as tronomers. On another visit it passed out of sight on 3 Jan. 1833. Its next appearance was in July 1839. It was found again late in No vember 1845, and in the following month an observation was made of one of the most re markable phenomena in astronomical records, the division of the comet. It put forth no tail while this alteration was going on. Professor Challis, using the Northumberland telescope at Cambridge, on 15 Jan. 1846, was inclined to distrust his eyes or his glass when he beheld two comets where but one had been before.
He would call it, he said, a binary comet if such a thing had ever been heard of before. His observations were soon verified, however. Late in August 1852, the larger came into view and three weeks later the smaller one, now much fainter than its former companion, was seen about 1,500,000 miles in the lead. Schia parelli's investigations showed it to be probable that the comet is the illuminated central mass of a stream of meteorites. The Bielid stream of meteors (or Andromedes, as they are also lcnown from the position among the stars from whith they seem to radiate) revolves around the sun in a period of 13 years, and the earth passes their orbit every year but meets the rnain swarm only when passing the point of inter section of the two paths. The meeting usually takes place on the 27th or 28th of November.