The prediction of the weather from natural indications has been attempted from time immemorial; but hitherto the weather prophets have been compelled to confess that " all signs fail in dry weather." Professor Houzeau, formerly of the Royal Observatory at Brussels, has been making observations for years, and has finally published a general table whereby he claims the weather may be predicted for a short time in advance with considerable certainty. The things to be observed are, the direction of the wind,the state of the barometer, and the state of the sky. These three states may be expressed thus: Barometer rising, falling, fixed, or very slow, falling fast, rising fast, rising slowly after sinking very low, sinking very low and for a long time. The sky is described as being blue, cloudy, rainy, or snowy, fine, cloudy with rain or snow at commencement of wind, fine with light clouds, veiled, hot after rain, covered, fine rain falling, hot after westerly rain, etc., etc. The directions of the wind are expressed in the points of the compass as usual. In the absence of all definitions we must say we think these terms exceedingly indefinite. To us, the differences between a fine sky and a blue sky, or a veiled sky and a covered sky are not quite apparent. The looseness of this terminology is scarcely indicative of scientific accuracy, although the antecedents of Professor Houzeau would lead us to expect it. We cannot give the table of indications prepared by Prof. Houzeau, but will give only some examples. A rising barometer, with blue sky and wind N., indicates cold and dry weather. Same, with cloudy sky, weather will clear up. Same, with rain or snow, wind will change to N.E., with alternate showers and sunshine. Barometer fixed, or very slow, with fine sky, wind N.E., the wind will continue, and weather become dry. Same, with cloudy sky, rain, or snow at commencement of wind, the same result may be expected as before. These examples will serve to show the method employed. It must be remembered, however, that if the predictions thus made should prove very accurate for the locality of Brussels, they would not be likely to be so in other places remote from that point, though it is fair to infer that if the states of the barometer, sky, and the wind are sufficient data in one place, they would, also, be enough in another. The interpretations would, therefore, be subject to amendment. For ourselves, we confess our faith is small, but as there is nothing apparently impossible nowadays, there may be something in Professor Houzeau's talle. Compressed Fuel from Coal Dust. In Great Britain the quantity of coal dust remaining unemployed is calculated at 28,000,000 of tuns. Various methods have been attempted to convert it into useful fuel by compressing it into cakes, but the operation is not sufficiently remunerative. In Belgium they follow another plan, which seems to answer better. They mix coal dust with 8 per cent of tar, and then press it into cakes, which are found to make excellent fuel for steam engines. The dross accumulated in iron works, to the amount of millions of tuns, is known to contain from 25 to 50 per cent of iron, but the difficulty of extracting is very great, the metal being intimately combined with various silicates, and other substances, which are not easily separated by fusion. Lime, indeed, will decompose these silicates, but the iron thus obtained is brittle. Nevertheless, M. Fleury has recently made a successful attempt to obviate this drawback by slacking the lime used for the purpose in water containing a certain proportion of some alkaline chloride. The ArcJritectural Review contains a description of a patented frost-proof tin pipe for gutters. Instead of being cylindrical like ordinary pipe, it is corrugated longitudinally, so that when water in it expands by freezing, the pipe also expands approximating the cylindrical form. The idea of making corrugated pipes for the above purpose is quite old, and has been the subject of applications for patents.
This article was originally published with the title "Prediction of Weather" in Scientific American 21, 7, 106 (August 1869)