James McCutcheon and co. Fifth ave. at 34th st. N. Y.

Illustrates the various stages in the growth and manufacture of flax. Free to domestic departments of high schools and colleges, freight charges collect.

FLOUR

Hecker-Jones-Jewell milling co. Produce exchange, N. Y.

Furnished only to schools in New York state.

Pillsbury flour mills co. Minn.

Consists of twelve samples showing the different stages of flour manufacFree, express charges to be guaranteed by applicant; weight about 18 lbs.

Washburn-Crosby co. Minn.

Supply of exhibits temporarily exhausted. Free to schools or educational institutions.

GRAIN

Commissioner of immigration, Winnipeg, Can.

Samples of grain and grasses in straw and samples of threshed grain.
GRINDING STONES

Pike manufacturing co. Littleton, N. H.

Shows the raw material and finished product. Free.

Horlick's malted milk co. Racine, Wis.

Exhibit shows wheat, flour, barley and barley malt. Free.

NEEDLES

Spool cotton co. 315 Fourth ave. cor 24th st. N. Y.

Limited number of needle specimen cases, showing needles in various

stages of manufacture. Free on application of principal.

NITRATE INDUSTRY

Chilean nitrate propaganda, 25 Madison ave. N. Y.

Limited number of lantern slides for distribution, which show the stages in the Chilean nitrate industry

Armour and co. Chic.

PACKING INDUSTRY

Exhibit of by-products. $10.00.

Morris and co. Chic.

Samples of tallow, glue fertilizers, showing by-products of packing industry. Free.

PAINT AND VARNISH

Sherwin-Williams co. 601 Canal road N. W. Cleveland, Ohio.

Shows raw material. Probably free.

PENCILS

Joseph Dixon crucible co. 501 Victoria bldg, St. Louis, Mo.

From crude graphite and cedar strips to the finished product. Free to schools.

Eberhard Faber, 37 Greenpoint ave. Brooklyn, N. Y.

Steps in the manufacture of a pencil from crude graphite and cedar strips to the finished product. Free.

PENS

Esterbrook steel pen mfg. co. Camden, New Jersey.

Shows by samples the steps in the manufacture of pens from the sheet steel to the finished product. 10c.

Spencerian pen co. 349 Broadway, N. Y. 25c.

PETROLEUM

Standard oil co. 72 West Adams st. Chic.

Samples of 21 petroleum products. Distributed only to large schools.

POTASH

German Kali works. 1901 McCormick bldg, Chic.

Sent only to institutions in which agriculture is taught.

RUBBER

United States rubber co. Broadway at 58th st. N. Y. $10.00.

SALT

Diamond crystal salt co. St. Clair, Mich.

Contains samples of crude salt and of salt in different stages of manufacture. Free to schools on payment of express charges; in middle west charges amount to about 75c.

Worcester salt co. 71-73 Murray st.

Samples of salt to schools. Free.

N. Y.

SHEARS

J. Wiss and sons co. Newark, N. J.

Shows steps in the manufacture of shears. Free, express collect; in middle west charges amount to between 20 and 30c.

SILKS

Belding bros. and co. 201 West Monroe st. Chic.

Silk exhibit. $1.25.

Corticelli silk mills, Florence, Mass.

Box of two cocoons, 5c; silk culture chart, 20c; silk culture cabinet, $1.25 if intended for educational exhibit in schools.

M. Heminway and sons silk co. 890 Broadway, N. Y.

Samples of silk cocoons, raw silk and silks in process of manufacture. Free, express charges collect; in the middle west the charges amount to between 30 and 40c.

lands, both through extensive travel and wide reading, have made it possible for him to produce a book which is indispensible to students of earth science in America.

INTRODUCTORY GEOLOGY. By T. C. Chamberlin and R. D. Salisbury, x+ 708 pages. Henry Holt & Co., New York, 1914. $2.00.

An abbreviation and simplification of the authors' College Geology, intended to present an outline of the essential features of geology with as few technicalities as the nature of the subject permits. Part I deals with geological processes, and the materials on which they operate, while the theme of Part II is historical geology. The book contains the high standards of the earlier geologies by the authors.

ALASKAN GLACIER STUDIES. By Ralph Stockman Tarr and Lawrence Martin. xxvii+498 pages. National Geographic Society, Washington, 1914. $5.00. To be reviewed later.

MINERALS AND THE MICROSCOPE. By H. G. Smith, xi+116 pages. D. Van Nostrand Company, New York, 1914. $1.25.

For those who are beginning the study of minerals and rocks in thin section with the microscope. Deals with the characters of minerals in various sorts of light, followed by descriptions of common rock-forming minerals, and hints on petrology. The subject matter is logically presented and the illustrations are exceptionally fine.

WATER Reptiles of the Past and Present. By Samuel Wendell Williston. viii+251 pages. The University of Chicago Press, Chicago, 1914. $3.00.

Professor Williston has been studying vertebrate paleontology for more than 40 years, and is one of the leading authorities in this branch of geology. In this book he has succeeded perfectly in his aim of "making the text understandable, and he hopes, of interest also to the non-scientific reader." Those who wish to add to their knowledge of the abhorrent serpents and the certain few poisonous snakes some knowledge of crocodiles, turtles, true lizards, and tuatera or beaked lizards of the past and present, cannot do better than to read this book.

THE NATURALISTS' DIRECTORY. A new edition of the Naturalists' Directory has just been published by S. E. Cassino, Salem, Mass. This directory invaluable to naturalists since it is the means of bringing together students and collectors in all parts of the world through correspondence. The directory contains an alphabetical list of English speaking professional and amateur Naturalists in all parts of the world, also a list of Scientific Societies and Periodicals. The price of the Directory is $2.50 in cloth binding and $2.00 in paper binding. Sent postpaid. As only a limited edition has been printed it is advisable for any one wishing a copy to order at once.

Volume XIII

FEBRUARY 1915

THE EUROPEAN WINTER AND THE WAR*

Number 6

By Robert DeC. Ward

B

Harvard University

EFORE considering the effect of the winter upon the military operations in Europe, we may very well review, briefly, the general climatic conditions of the western and eastern theaters of war.

Western and northwestern Europe are roughly similar, climatically, not to the eastern United States but to the Pacific coast of North America north of Oregon. As we go east across Europe the winters become more and more severe, and we find ourselves in another climatic province, which extends from western or central Germany across Russia and far east across Siberia. A somewhat similar "Siberian" climatic region is found in western Canada, east of the Rockies, and extending some distance into the United States. The eastern war area is climatically intermediate between western Europe and central Russia, being less extreme than the latter and more extreme than the former. The plains of Hungary are roughly similar to our own Great Plains, and the Mediterranean portion of Europe is climatically like California. Western and northwestern Europe are freely open to the sea. Their prevailing westerly and southwesterly winds are tempered by the relatively warm Atlantic waters. Hence the winters are mild. No such extremes of cold occur as are found farther east, at a greater distance from the sea. The average midwinter (January) temperatures over the western war zone are between 35° and 40°, i. e., about the same as those of Baltimore and Washington. In the eastern war area, the midwinter (January) mean temperatures run about 10° lower, or between 25° and 30°. Boston and Buffalo are much like Poland in their average midwinter temperatures. The lowest thermometer readings which observers in the western war zone are likely to make during an ordinary winter average between 5° and 15° Fahr., but they are between -5° and -15° Fahr. in the eastern war area. In any given cold winter, however, the temperatures may fall 10° or so lower than these averages. The effect of winter cold upon navigation is an important factor in all naval warfare. In western Europe, the North Sea harbors remain open, and navigation is not often or seriously handicapped, although occasionally, in severe winters, there is difficulty with the ice along the coasts and in the mouths of the rivers. In the Baltic, on the other hand, ice makes more trouble. Much of this sea is choked by ice, and most of the harbors and even the large rivers freeze. Ice-breakers, however, may be used to keep open the important ports when necessary, except in the farther north. The winters

An article by the writer, entitled "The War and the Weather During the First Three Months of the Fighting," appeared in the Popular Science Monthly for December, 1914, and considered the weather influences upon the military and naval operations from Aug. 1 to Oct. The present article will deal chiefly with the period from Nov. 1 to Jan. 31.

31.

vary a good deal in their severity, and in their effects upon the freezing of the Baltic harbors. Over the eastern war zone the rivers, lakes and streams are ice-bound. The Vistula is usually frozen at Warsaw from the end of December until early in March. The Neva was this year closed to navigation early in November.

European winter weather goes through a series of more or less systematic changes under the control of passing storms which alternate with spells of finer, drier and more settled atmospheric conditions. The weather of Europe is mainly controlled by storms which, coming from North America, or beginning in the ocean area around Iceland, pass northeastwards across the northeastern Atlantic and over or near to northwestern Europe, their influence extending 200 or 300, or more, miles south of their centres. Many storms which we have experienced on our side of the Atlantic later cause snow and rain and gales on the other side. As the storms approach, and pass by, the wind-vanes of central Europe turn, with characteristic regularity, from southeast through south to west, a succession of changes which is, of course, perfectly familiar to us here. Europe thus undergoes many variations of temperature and of weather, as we do, but these changes are, on the whole, less rapid, less frequent and less violent than our own because European storms usually move more slowly and are less violent than ours. The Atlantic Ocean, the Channel, the North and Baltic Seas, and the adjacent coasts, being in the region which is nearest the storm tracks, are all subject to frequent and severe winter gales, with rain and sleet and snow-squalls, rapidly shifting winds, and thick weather. Such conditions make navigation in those more or less landlocked waters difficult and dangerous.

In comparing the western and the eastern theaters of war in winter, it is to be noted that both have advantages and both have disadvantages, from a military point of view. The temperatures average higher in the west. Therefore Belgium and France have more rain, more sleet, more mud, more "slush", than are found in eastern Germany, Austria, and Poland. The cold clear spells are of shorter duration in the west. They are more frequently interrupted by milder temperatures and thawing weather. But this physical relief, from the cold, is gained at the expense of added discomfort and suffering on account of the dampness, the hard marching, and the difficulties of transportation. In the west, the air is damper, so that the same, or even a more moderate degree of cold, often gives a greater sense of chill than where the air is drier. In the eastern war zone there is the disadvantage of greater and more continuous cold, but the advantage of somewhat more settled weather, and usually of more continuously frozen ground. In Belgium and eastern France the Germans find themselves in somewhat milder winter conditions than those which prevail over much of their own country farther east. If the Germans should penetrate into Russia, or the Allies into Germany, both sides would experience a gradually increasing severity of winter cold. Again, the Russians, in advancing westward, would be entering a milder climate than their own.