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HANDY BOOK

OF

METEOROL O G Y

BY

ALEXANDER BUCHAN, M.A.

SECRETARY OF THE SCOTTISH METEOROLOGICAL SOCIETY

SECOND EDITION

WILLIAM BLACKWOOD AND SONS

EDINBURGH AND LONDON

MDCCCLXVIII

196. f. 8

The Right of Translation is reserved

PREFACE TO THE SECOND EDITION.

The object which the author of this treatise has kept steadily in view has been to set the subject of Meteorology before the general mind in such a way as shall engage on its behalf a widespread interest, to which, from its intimate connection with our welfare and happiness, it is in every way entitled. Frequent occasion is taken to point out the bearings of the science on the practical affairs of life. The information is brought down to the present time, thus rendering it a handy book of reference on subjects connected with weather and climate.

The Isothermal Charts for July, January, and the year, Plates IV., V., and VI., have been adapted from Dove's Monthly and Yearly Isothermals, 1864, and the same author's Charts given in The Distribution of Heat over the Surface of the Globe, 1853.

The Isobarometric Charts for July, January, and the year, Plates I., II., and III., are new. They formed the subject of a paper read before the Royal Society of Edinburgh on the 16th March 1868. The mode of their construction is described in the text. Though the first attempts at the construction of such charts, they may be regarded as close approximations to the statement of the atmospheric pressure of the globe, owing to the comparatively large number of places from which barometric observations have been obtained, and to the circumstance that fewer places are required to represent the pressure over any portion of the earth's surface than are required to show the temperature, the winds, or the rainfall.

Since the information conveyed by isobarometric charts forms the basis of Meteorology, it has been necessary, in preparing this edition for the press, to recast the greater part of the work. The chapters on “The Distribution of Atmospheric Pressure over the Globe," and “The Relation of Atmospheric Pressure to the Temperature,” are wholly new, and the Chapter on “Winds” is almost altogether new. The intimate connection of temperature with pressure is illustrated by the exceptional weather of last year (1867), the chief instances adduced being the mild weather of February ; the unprecedentedly cold weather of March, which proved so injurious to vegetation ; the cold weather of July, so disastrous in its effects on the crops; and the singularly fine weather of November. The great frost of Christmas 1860, the warm weather of September 1866, and the cold weather in the south of Europe in January 1868, are considered in the same relations. Attention is thus directed to the proximate causes of exceptional weather, and remarks are made with the view of suggesting how this knowledge may be turned to practical account. The importance of Iceland as the key to the climates of the greater part of North America and Europe is pointed out.

The subject of STORMS is more specially discussed, as being, from the practical application of the results of the inquiry to the prediction of storms, and consequently to the saving of life and property, a question the im

portance of which it would be difficult to overestimate. As the subject has been considered from the observational side, it follows that the law of storms, so far as enunciated, is to be regarded not as mere theory, but as the result of generalisations of observed facts. In the few cases where theoretical opinions are advanced, their theoretical nature is distinctly stated. The proximate cause of high winds is illustrated by the Great Hurricane which was so severely felt at Edinburgh on the 24th January 1868. The observations made by observers of the Scottish Meteorological Society at the time, supplied the materials for placing the relation of wind-force to differences of pressure in a very clear light. A new chapter has been added on “ Weather and Storm-Warnings.”

Other features of storms yet remaining to be investigated, and many undetermined points, in reference particularly to the diathermancy and distribution of the aqueous vapour of the atmosphere, solar and terrestrial radiation, the temperature of the soil, and ocean meteorology, are stated, in order that the attention of meteorologists may be directed to the most fruitful fields of research which the science presents.

Meteorology has been too long treated with neglect, both in popular and in liberal systems of education. In the popular education of this country it cannot be said to hold a place; and even in a University course, though classed among the subjects embraced by Natural Philosophy, its position in the curriculum of studies is little more than nominal. The causes of this neglect are not far to seek :—the chief being the absurd pretensions of weather-prophets and other prognosticators; the free and bad use long made of electricity and other imperfectly understood agents to explain the causes of atmospheric disturbances; the fewness of the observed

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