not likely to cease before evening, and may even continue to fall during night-time. Halos round the sun and moon are in the majority of cases followed by stormy weather, because the cloud-sheet of ice crystals, in which the halos are produced by the refraction and reflection of the light rays by the crystals, is always found in front of a depression, though it may also occur without the presence of a depression. Other maxims, again, have considerable value in some localities, but are inaccurate in others. In mountain districts the cloudcap that forms on the mountain-tops is often used as an indication of the coming weather. Statements regarding the stormy presage of a red sky in the morning, or of the happy augury of a grey dawn, are not always trustworthy, for their accuracy depends entirely upon the meteorological situation, and a good deal of expert knowledge is required before such signs can be correctly interpreted. But, on the other hand, some "proverbs" are quite unworthy of serious attention. The effect of the new moon upon the weather, so widely believed in, has been investigated and found to be nonexistent. The belief that six weeks of daily rain will follow a wet St. Swithin's Day is equally absurd, for the common occurrence of more frequent rain after that date is due merely to the seasonal change, from the dry early summer to the much wetter late summer and early autumn, to which our Islands are subject. But the old maxims provide a very interesting study, as those can testify who have read the volume on Weather Lore, compiled by Mr. Richard Inwards. BIBLIOGRAPHY CLARKE, G. A., Clouds. GEDDES, A. E. M., Meteorology, an Introductory Treatise. VOL. III-15 MCADIE, A., Principles of Aerography.1 MILHAM, W. I., Meteorology.1 MOORE, W. L., Descriptive Meteorology1 PICK, W. H., Short Course in Elementary Meteorology. SALTER, M. DE C., Rainfall of the British Isles. SHAW, W. N., Forecasting Weather. 1 These books are American. APPLIED SCIENCE I. THE MARVELS OF ELECTRICITY The Age of Electricity Ο UR age is the age of electricity. The remarkable revolu tion which the practical application of electricity has effected in recent years is one of the wonders of modern life. To Electrical Engineering Science the civilisation of to-day owes more than is readily realised. It has solved many great problems which modern conditions of life called into being, and which had to be solved if further progress was to be looked for. Professor J. A. Fleming, who has given fifty years to studying the problems of electricity, has said that the outlook for electrical engineering has vast possibilities "which may materialise at any time and make ancient history of our present achievement," great as that is. The records of the past half-century are wonderful enough; the next fifty years of electricity, it is interesting to learn from such an authority, "is a subject for attractive meditation." Space and time have been almost annihilated; the transmission of energy, the development of production, and distribution of electrical power all suggest great possibilities. We have seen in previous sections of this work the interesting stage Physicists and Chemists have reached in their investigations into the constitution of the atom, and how these investigations have transformed our fundamental conception of matter. The discovery of the electron as a mobile constituent of the atom of matter has, Sir Ernest |