THE RAIN PREDICTOR.

Daily Telegraph (Napier), Issue 3590, 13 January 1883, Page 4

THE RAIN PREDICTOR.

Professor Piazzi Smyth, the AstronomerEoyal for Scotland (says an English paper), has drawn attention to what promises to be an imporatant contribution to meteorological science. The daily weather charts and forecasts are doubtless of great service ; but itiswell known thatthe previsions of these are not only sometimes incorrect, but rarely extend beyond twenty-four hours. Well, for some "time past opticians have been making pocket spectroscopes, by means of which persons may ascertain the probability or otherwise of rain falling. All one has to do is to look at the sky through such an instrument, when, in addition to the prismatic colors and the thin solar-originated lines, he may see a dark band stretching across the spectrum. This band is designated the "rain-band," and is caused by the presence of watery vapour in the atmosphere. In proportion to the intensity of this band is the quantity of water in suspension. When the spectroscope registers 0 or 1, it is found that no rain falls ; but when the register is 2, rain begins to fall, and when 3 it maybe very heavy. This ingenious instrument, however, does not enable its possessor to foresee beyond a few hours ; but the discovery made by Professor Smyth is likely to extend the range of prevision very considerably. On the morning of 4th September, when the small spectroscope correctly registered 0, Professor Smyth says ho was startled to find in a larger instrument that almost every trace of the rain-band was gone. '' I not only felt sure of no rain falling next day," the Professor writes, "or for .several days after, but thattheweathermust becoming on colder as well. Therefore it was that I took the step of instantly writing as I did to a local paper [the Scotsman], promising the perplexed fanners dry weather at last, though opposed to the forecasts of the Meteorological Office," and meteorologists in various parts of the country have expressed to Professor Smyth their satisfaction with the prevision.