RAINBOW. See Meteorology and Optics.

Lunar Rainbow. The moon sometimes exhibits the phenomenon of an iris or rainbow by the refraction of her rays in drops of rain during the night-time. But this phenomenon is very rare. In the Philosophical Transactions for 1783, however, we have an account of three which were seen in one year, and all in the same place; it is communicated in two letters by Mr Marmaduke Tunstall. The first was seen on the 27th of February 1782, at Greta Bridge, Yorkshire, between seven and eight at night, and appeared in tolerably distinct colours, similar to a solar one, but more faint, the orange colour seeming to predominate. It happened at full moon, at which time alone they are said to be always seen. Though Aristotle is stated to have observed two, and some others have been seen by Snellins, Mr Tunstall could only find two described with any accuracy; one by Plot, in his History of Oxfordshire, which was seen by him in 1675, though without colours; and the other seen by a Derbyshire gentleman at Glapwell, near Chesterfield, described by Thoresby, and inserted in the Philosophical Transactions, No. 331. This was about Christmas 1710, and is said to have had all the colours of the iris solaris. The night was windy; and although there was then a drizzling rain and a dark cloud, in which the rainbow was reflected, it proved afterwards a light frost.

Two others were afterwards seen by Mr Tunstall. One of these was observed on the 30th of July, about eleven o'clock, which lasted about a quarter of an hour, but without colours; and the other, which appeared on the 18th of October, was perhaps the most extraordinary one of the kind that had ever been seen. It became visible about nine o'clock, and con- RAISEN-MARKET, a town of the county of Lincoln, in the hundred of Walshcroft, and in Lindsey division. It is situated near the navigable river Anklom, and has a market, which is held on Saturday. The population amounted in 1801 to 774, in 1811 to 964, in 1821 to 1166, and in 1831 to 1428.