Democratic Sentinel, Volume 20, Number 19, Rensselaer, Jasper County, 15 May 1896 — Registering Sunshine. [ARTICLE]

Registering Sunshine.

The heliograph, although not of recent invention, is now coming more generally into use since the importance of registering the number of hours of daily sunshine becomes more popularly appreciated. A recent publication of Professor Kremser estimates the number of heliographs now in use at about fifty in Great Britain, thirty in Germany, twenty-five in France, eighteen in Austria, sixteen in Italy and twelve in Switzerland. The apparatus is automatic. Sunshine registers itself through lenses, for as soon as the sun comes out of the clouds sufficiently it will burn a paper underneath the lens, leaving a black mark thereon. Since the hours of the day are marked on paper it will be apparent with approximate exactness how many hours each day the sun really shone. The results are very surprising indeed. For instance, the daily average of sunshine for several years amounted in Scotland to 2 hours; Ireland 3 1-2 hours; England, 4 hours; Germany, 4 1-2 hours; France, 5 hours; Switzerland, 5 1-4 hours; Austria, 6 hours, and Spain, 71-2 hours. It is shown that there is more sunshine in the south than there is in the north, and also more in the east of Europe than in the west. Near mountains the frequency of fogs lessens the hours of sunshine. Thus the observatorw on Ben Nevis shows less than 11-2 hours, almost an hour less than elsewhere in Scotland. The formation of smoke near great cities and manufacturing centres also lessens the hours of sunshine. The interior of London shows but 21-2 hours in Greenwich, and 4 to 41-2 hours elsewhere in southern England.—Chicago Inter-Ocean.