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the immense difficulties surrounding such an undertaking, his civil-service reform pledges were carried out as consistently as possible. He was renominated for the Presidency at Saint Louis, June 7, 1888, but was defeated, receiving only 168 electoral votes to Harrison's 233. At the National Democratic Convention of June, 1892, he was nominated for the Presidency on the first ballot, and in November was elected, receiving 277 electoral votes against 145 for Harrison (Republican) and 22 for Weaver (Populist). During his second term, in the face of the violent opposition of the mass of his own party, he exerted himself unflinchingly for the maintenance of the gold standard. He called an extra session of Congress in the summer of 1893, and secured the repeal of the Sherman Act of 1890, requiring the Government to make large purchases of silver bullion. He maintained the gold reserve by successive issues of Government bonds. When the Democratic majority of Congress passed a tariff act, he allowed it to become a law without his signature, considering many of its provisions in adequate. During the great railroad strike at Chicago in 1894 he ordered out the United States troops to "prevent the obstruction of the mails," although Governor Altgeld, of Illinois, who had not asked for the troops, protested vigorously against the measure. In the domain of foreign affairs, Mr. Cleveland's second adminstration was signalized by his withdrawal from the Senate of the Hawaiian Annexation Treaty negotiated by Presi dent Harrison; the upholding and advancement of the Monroe Doctrine by his vigorous and successful insistence upon the submission to arbitration of the long standing boundary dispute between Great Britain and Venezuela; and the promulgation of the Bering Sea arbitration award. These and other features of his administration are interestingly discussed by Mr. Cleveland in his book, Presidential Problems (1904). In con

sequence mainly of Mr. Cleveland's position on the currency question, his administration was not indorsed by the Democratic National Convention of 1896. In the ensuing Presidential campaign he supported General Palmer, the candidate of the Sound-Money Democrats. After his retirement, he lived at Princeton, and lectured at the university there. In 1905 as a result of a change in the controlling interests of the Equitable Life Assurance Society, Mr. Cleveland was appointed one of the trustees of the majority stock owned by Thomas F. Ryan, to act in the interests of the policy holders. Consult: Whittle, Grover Cleveland (London and New York, 1896); Peck, Twenty Years of the Republic (New York, 1906), and Hensel and Parker, Life and Public Services of Grover Cleveland (New York, 1906). CLE/VENGER, SHOBAL VAIL (1812-43). An American sculptor, born at Middletown, Ohio. He first became known through his work as a stonecarver in Cincinnati, and afterwards opened a studio in New York. He executed busts of Clay, Webster, Van Buren, Allston, Everett, and others. His portrait bust of Webster has been used on a United States postage-stamp, and is considered the best likeness of that statesman. He realized his own deficiencies in artistic education, and took advantage of an opportunity to go to Rome in 1840. While there he produced his "North American Indian," which is characterized by the sincere, bold treatment and skill in handling his material shown in all Clevenger's work. But for

his early death, which occurred while he was on his way home, he would probably have attained high rank in his profession.

CLEVES, klēvz (Dutch Kleefs, Ger. Kleve, Fr. Cleves). A German town of Dutch origin, and former capital of a duchy of the same name, situated in the Rhine Province of Prussia, about five miles from the frontier of the Netherlands (Map: Prussia, B 3). It is built on three hills, and has still retained some of its Dutch characteristics. It contains an old palace, the former abode of the Dukes of Cleves, now used as a lawcourt and prison; an old Rathaus, with a number of antiquities and paintings; and an old Catholic church, built in Gothic style, and containing the tombs of the counts of Cleves. In the vicinity of the town are situated chalybeate springs. Cleves is frequented as a summer resort by the Dutch. Population, in 1900, 14.684; in 1905, 16,433. The Duchy of Cleves, which arose in the Middle Ages, and which at the time of the Reformation was united with the duchies of Jülich and Berg, passed in the seventeenth century into the possession of Brandenburg.

It was

wrested from Prussia in the course of the Na

poleonic wars, but restored in 1815.

CLEW. See SAILS.

CLEWS, HENRY (1830-). An American banker, born in Staffordshire, England. He entered mercantile pursuits in New York City in 1845, became a member of various firms, and in 1877 organized the firm of Henry Clews and Company. He was a founder of the Union League Club, New York City, and also long treasurer of the American Geographical Society and of the Society for the Prevention of Cruelty to Animals. He has published Twenty-eight Years in Wall Street (isss), and The Wall Street Point of View (1900).

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CLICHY, or CLICHY-LA-GARENNE, kle'shè'là-gà'rèn'. A northwestern suburb of Paris, France. Population, in 1901, 39,291.

CLICK-BEETLE. A beetle of the family Elateride, also known as elater, snapping-bug, and skip-jack, on account of its acrobatic performances. When disturbed these beetles curl up their legs and fall to the ground, where they lie rigid on their backs for some moments, and then begin a series of springs into the air, accompanied by a clicking sound. When the beetle succeeds in landing on its feet, it runs off. In regard to the springing, Le Conte says: "This is effected by extending the prothorax so as to bring the prosternal spine to the anterior part of the mesosternal cavity; then, suddenly relaxing the muscles, so that the spine descends violently into the cavity, the force given by this sudden movement causes the base of the elytra to strike the supporting surface, and by their elasticity the whole body is propelled upward." The larvæ, known as wireworms, are hard, brownish-yellow,

and may live several years before gaining maturity. Most of them are found under bark and in rotten wood, but some live on the ground on the roots of grass, Indian corn, and other grains, as well as on those of certain vegetables. When numerous enough they may do considerable damage. Fall plowing is said to be the most effective remedy against them. Of the 7000 described species of elaters 500 occur in North America. The most conspicuous click-beetle found in the United States is the eyed elater (Alaus oculatus), a grayish black beetle with two large black eye-like spots on the prothorax; its larvæ live in rotting stumps. In the tropics of America there are luminous species belonging to the genus Pyrophorus, as the cucuyo (Pyrophorus noctilucus) and others.

BIBLIOGRAPHY. De Candeze, Monographie des élaterides (4 volumes and 3 supplements, Liège, 1857-1881); Le Conte, "Revision of the Elateride of the United States," in Transactions of Philosophical Society, vol. X. (Philadelphia, 1853); Horn, Papers in Transactions American Entomological Society, vols. xii., xiii., xviii. (Philadelphia, 1885, 86, '91). See FIREFLY.

CLI'DOMAN'CY. See SUPERSTITION.

CLIENT (Lat. cliens, cluens, hearer, from cluere, Gk. Kλveɩ, klyein, Skt. śru, to hear; connected ultimately with AS. hlud, Engl. loud). In law, one who consults or retains an attorney or counselor-at-law for advice, or to prosecute, manage, or defend an action at law, or to represent him in any proceedings or business matters. The client's relations with the attorney are in the highest degree confidential, and the client is protected by the most stringent rules of law in making disclosures of his private affairs to his legal adviser. See ATTORNEY; PRIVILEGED COM

MUNICATION.

CLIFF (AS. clif, Icel., OS., Dutch klif, from Icel. klifa, ME. cliven, to climb). A precipitous slope of the land surface. Cliffs may be formed in three ways: (1) by the erosive action of water; (2) by the disintegrating influence of rain, frosts, and the atmosphere, or weathering; (3) by dislocations of the earth's crust. On rocky coasts cliffs are carved out by the force of waves, which beat against the shore-line, and by weathering of the rock that lies above the reach of the waves. The cliffs of Dover and of the Orkney and Shetland islands are notable examples of sea-cliffs. Gorges, cañons, and ravines, which are characterized by steep walls, are excavated by the erosion of running water; they are usually found along the upper courses of rivers. Cliffs may mark the line of outcrop of stratified rocks, and in such cases are usually to be traced to differential weathering of hard and soft strata. In regions of disturbance, cliffs are formed by faulting, which exposes a vertical rock-face or scarp. Many of the notable elevations in the Adirondacks are characterized by faulted scarps. See SHORE; CAÑON; FAULT; etc.

CLIFF-DWELLER. A name frequently used to designate the supposed extinct builders of the numerous ancient cliff ruins scattered throughout the cañons and mesas of the arid Southwest, along the upper waters of the Colorado and Rio Grande-in Utah, Colorado, Arizona, and New Mexico. The ruins are either upon the summits of the mesas or on shelves in the rock-walls of the cañons. For a long time their origin was

a subject of much speculation; but recent ethnologic investigation has proved that these ruins are not the work of any extinct or distinct race, but were built by the immediate ancestors of the modern Pueblo Indians (q.v.), some of whom, in fact, notably the Hopi, still have their villages upon the summits of almost inaccessible mesas for better protection against the wilder Navajo and Apache, by whom they are surrounded. During the last few years the Bureau of American Ethnology has been engaged in a systematic survey of these ruins. See G. Nordenskiold, The Cliff Dwellers of the Mesa Verde, Southwestern Colorado (New York, 1902). See ARCHEOLOGY, AMERICAN. For illustration, see Casa Grande.

CLIFFORD, GEORGE, Earl of Cumberland (1558-1605). An English naval commander and buccaneer, born in Westmoreland. He took the degree of M.A. at Cambridge in 1576, and in 1588 commanded the Elizabeth Bonaventure, in the actions against the Spanish Armada. Thenceforward he was active chiefly in fitting out and conducting piratical expeditions. Of these the most important were one undertaken with seven sail, in 1589, which captured several rich prizes, and one with twenty sail, in 1598, which took San Juan de Puerto Rico, but failed in an attempt to intercept the Spanish treasure-galleons.

CLIFFORD, LUCY LANE (Mrs. William Kingdon). An English novelist. She was the daughter of John Lane of Barbados, and in 1875 married William Kingdon Clifford, the distinguished mathematician. Mrs. Clifford is best known by Love Letters of a Worldly Woman (1891) and Aunt Anne (1892). Among her other books are: Any How Stories (1882; reissued with additions, 1899); Mrs. Keith's Crime (1885); The Last Touches (1893); A Wild Proxy (1894); A Flash of Summer (1895); Mere Stories (1896); The Dominant Note and Other Stories (1897); and Margaret Vincent (1902). She also produced several plays, of which The Likeness of the Night (1900) is most noteworthy.

CLIFFORD, PAUL. The hero of Bulwer's novel of the same name, a highwayman who is finally reformed through love.

CLIFFORD, NATHAN (1803-81). An American jurist, born in Rumney, N. H. He graduated at the Hampton Literary Institution, was admitted to the bar, and commenced practice in York County, Maine, in 1827. He was a member of the State Legislature from 1830 to 1834, was Speaker of the House for the last two years, and was Attorney-General from 1834 until 1838. He served in Congress from 1839 to 1843, and in 1846 was Attorney-General in President Polk's Cabinet. At the close of the Mexican War he went as a special United States envoy to Mexico, and negotiated a treaty by which California and other territories became a part of the United States. In 1858 he became, by President Buchanan's appointment, an associate justice of the United States Supreme Court, and in 1877 was president of the Electoral Commission (q.v.) that decided the Hayes-Tilden Presidential controversy. He published United States Circuit Court Reports (1869).

CLIFFORD, WILLIAM KINGDON (1845-1879). An English mathematician and physicist, born at Exeter. He was educated at a school in his na tive town, at King's College, London, and at Trinity College, Cambridge, where he was second

wrangler in the mathematical tripos of 1867. In August, 1871, he was elected to the chair of mathematics and mechanics at University College, London, which post he retained until his untimely death at Madeira, March 3, 1879. Clifford first established his reputation as an original thinker with the faculty of expressing scientific thought in plain and simple language by a lecture at the Royal Institution, On Some of the Conditions of Mental Development. He was a valued member of the London Mathematical Society, contributing to the Proceedings; for a time he acted as secretary, and afterwards vicepresident of the mathematical and physical section of the British Association; he also lectured to the Sunday Lecture Society on such subjects as Ether; Atoms; and The Sun's Place in the Universe, and took an active interest in popularizing science. The versatility of his mind in philosophical and scientific discussion was further shown by his varied contributions to periodical literature. Besides these articles, and many papers on mathematics, he issued the first part of a larger text-book, Elements of Dynamics (1878). See Clifford's Lectures and Essays, edited by Leslie Stephen and F. Pollock (London, 1879), which contains a biographical sketch by

the latter editor.

CLIFFORD'S INN. An inn of Chancery, attached to the Inner Temple, in London, built in 1345, and named after Robert de Clifford, who lived in Edward II.'s reign. Like the other Inns of Chancery it is now used for office and business purposes.

CLIFF-PLANTS. A group of drought-plants, Xerophytes (q.v.), found chiefly on river, lake, or sea cliffs. See ROCK-PLANTS.

CLIFF-SWALLOW, or EAVES-SWALLOW. A swallow (Petrochelidon lunifrons) familiar throughout North America as one of those that make their nests about barns and outhouses. (See BARN-SWALLOW.) It is distinguished from other semi-domestic swallows by its short, square tail, reddish rump, grayish breast and collar, and white forehead; and by the fact that it places its flask-shaped nests of mud always on the outside of the building, unlike the fork-tailed true barn-swallows, which go inside the building to nest. This swallow originally nested in colonies wherever a rocky cliff afforded a chance to fasten their nests in close companies upon its face. (See Plate of FAMILIAR SWALLOWS.) These nests were globular, with a spout-like neck, forming the entrance, and were formed of pellets of mud, and lined with grass and feathers. As soon as human settlements began near their resorts, these swallows abandoned the cliffs for the more secure, better-sheltered place under the eaves of such buildings as they were permitted to occupy; and as the spread of civilization has finally covered most of the range of the species, only a few places in the remote West remain where these birds may be seen nesting after their primitive habit. In the eastern part of the country interesting modifications of habit have followed their long-continued association with man-among others, a disposition to make a much simpler style of nest, leaving off the domed roof and flask-like entrance, and forming little more than a cup in its place, since the overhanging eaves keep off the rain and conceal the sitting bird. This genus is almost cosmopolitan, has similar habits nearly everywhere, and in all countries attaches itself

to and is welcomed by civilization. Consult Ingersoll, Wild Life of Orchard and Field (New York, 1902).

CLIFTON. A beautiful and favorite water

ing-place in the southwest of Gloucestershire, England, forming the western suburb and part of the Parliamentary borough of Bristol (Map: England, D 5). It has a tepid spring of 73° F., which contains carbonic acid and salts of magnesia. The deep valley of the Avon is here spanned by a graceful suspension bridge. Population, in 1901, 44,400. See BRISTOL.

CLIFTON, or SUSPENSION BRIDGE. Former name of the town of Niagara Falls (q.v.), Ontario, Canada.

CLIFTON FORGE.

A town in Alleghany

County, Va., 231 miles west by north of Richmond, on the Chesapeake and Ohio Railroad (Map: Virginia, E 4). It has a handsome Y. M. C. A. building and a railway hospital. There are extensive railway shops and important iron interests. Population, 1906 (local est.), 4000.

CLIFTON SPRINGS. A village in Ontario County, N. Y., about 28 miles (direct) southeast of Rochester; on the Lehigh Valley and the New York Central and Hudson River railroads (Map: New York, C 3). It is famous for its sulphur springs and the well-equipped Clifton Springs Sanitarium, the latter surrounded by three parks. Settled about 1850, Clifton Springs was incorporated as a village in 1859. Population, 1900, 1617; 1905, 1586.

CLIM, klim, or CLYM OF THE CLOUGH,
kluf (Clim of the valley, Icel, klofi, ravine, from
klufa, to split, AS. cleofan, to cleave). An Eng-
lish archer, said to have lived one generation pre-
vious to Robin Hood. He is known through the
old ballad Adam Bell, Clym of the Cloughe, and
The story runs that
Wyllyam of Cloudeslee.
these men were outlawed for stealing venison,
and passed through many adventures and fights
with the sheriff's, justices, and mayor of "Merrie
Carlile." They went to the King for pardon; but
he would have hanged them but for the Queen.

The ballad is far older than the oldest copy ex-
A frag-
tant, printed by Copeland about 1550.
ment of an older one exists, recovered by Payne
Collier. In this ballad William of Cloudeslee
shoots an apple from his son's head after the man-
ner of William Tell, of the Continental legend.

CLIMACTERIC YEAR (Lat. climacteri cus, Gk. «λiμaktŋpikós, klimaktērikos, climacteric, from кλμáктηp, klimakter, round of a ladder. dangerous point in life, from κλiμaž, klimax, ladder, staircase). The year in the life of a woman during which she undergoes what is commonly called the 'change of life,' and which generally falls between her forty-fifth and fiftieth years. The term 'climacteric years' was once applied also to certain years in man's life, which were long believed by the disciples of astrology to have been the critical points of his health and fortune. Crises of this kind were, namely, supposed to be reached in the twenty-first, the thirty-fifth, the forty-ninth, and the sixty-third years of man's life. The most important of all was the sixtythird year, which was called-by way of eminence

the climacteric year, or the "grand climacteric." This year was supposed to be fatal to most men, owing to the fact that sixty-three is the product of the two mystical numbers seven and nine.

CLIMATE (OF. climat, from Lat. clima, Gk. λipa, klima, region, slope, from κλive, klinein, to incline). A word used in meteorology to indicate the summation or general result of all the solar and terrestrial influences that affect animal or vegetable life. It is possible, in fact, to disregard the relation to life, and consider only the meteorological phenomena as such, or the phenomena that affect any phase of our activity. Thus, one may ask, How does the climate favor navigation by sailing vessels, or the use of the wind as a motive power? In one region the climate may favor the development of a certain disease; in another, it may favor the development of special varieties of plants or animals. The specific features that favor the growth of either plants or animals, enabling them to make a specific spot their home, are oftentimes so obscure as to elude our observation and record; therefore, climatology is, in many respects, still an unsatisfactory study; but it has made such progress in the past fifty years as to have become exceedingly important to many classes of industries, as well as to physicians, naturalists, and agriculturists. Some varieties of plants are so dependent upon the nature of the soil in which they grow that Dr. Milton Whitney, of the United States Department of Agriculture, has advocated defining climatology as that which concerns the soil around the roots of the plant; but this is too narrow a view of the subject.

According to the usage of classic Greek, climate concerned principally the temperature of a place as regulated by the altitude of the sun at midday. As this varies with latitude, the ancients divided the known globe into zones two degrees broad in latitude, each of which was supposed to have its climate. At the present time, by combining the accumulated work of thousands of observers, we divide the globe into irregular regions, each of which differs from its neighbor in some important climatic condition as to temperature, rainfall, pressure, moisture, or the inclination of the sun and the amount of cloudiness. In the extensive works of the most eminent writers on climatology, especially those of Dr. Julius Hann, of Vienna, a large number of meteorological items are enumerated as being essential to a complete study of the climate of any place. These items include not merely the mean temperature, rainfall, cloudiness, the barometric pressure and relative humidity, but also the variations of these quantities, viz. their highest and lowest values each day, or month, or year, and the liability to sudden rises or falls. For navigation and the use of windmills, we need to know the average velocity of the wind, and perhaps especially the number of hours during which the wind exceeds a specified limit. With reference to the growth or importation of tender plants, the agriculturist needs to know the mean dates of the last frost of spring and the first frost of the autumn, the difference between which is ordinarily called the growing season. Since the establishment of the fact that the germination of seed, the growth of the plant, and the ripening of the harvest requires a certain amount of heat or molecular energy, efforts have been made to determine the thermal constants for many plants, and for each phase in growth. This 'thermal constant' is usually expressed as the sum total of the average daily temperatures when such temperatures are

above 42° F. There is also a 'rainfall constant' peculiar to each species of plant, the nature of which has been investigated by Linsser, who has shown that plants are able, by gradual evolution, to change their own thermal and aqueous constants, and eventually adapt themselves to a change in climate. Linsser's laws serve as a guide to those who would transplant a species from one part of the world to another of different climate.

In the study of climate with reference to navigation, we have to consider the frequency of destructive storm-winds. Charts showing this factor have been published for all the oceans and seas by the hydrographic offices of England, France, Holland, Russia, and the United States. In addition to this, for the special benefit of sailing vessels, Galton has shown how to prepare charts showing, for each square degree, the progress that a vessel of a certain size and rig would make if her sails were set so that she should go in a certain direction. From the point of view of insurance, both life insurance and fire insurance, the destruction by wind, hail, and lightning has been studied; these data, being plotted on charts, show the climate of the country from that point of view. Perhaps the most general idea of the distribution of climate is given by charts which show the frequency per month or year with which storm-centres pass over a given locality, and the direction in which they pass. A map of such frequency for the eastern portion of the United States was first published in the Statistical Atlas of Gen. Francis A. Walker in 1874, and the most extensive publication of this kind was published in 1893 as Weather Bureau Bulletin A, showing the frequency of storm-paths for all parts of the Northern Hemisphere. The wind, rain, and temperature are so distributed around a storm-centre that, when its location is known, the distribution of all the others can be closely estimated. In general, in the Northern Hemisphere, the regions that lie to the south of the paths of the storm-centres have prevailing warm, moist, southerly winds followed by occasional sudden changes to cool, dry, westerly winds. This change occurs with every passing storm-centre, but the prevailing weather is clear and pleasant. Stations lying on the north of the paths of the storm-centres have prevailing easterly winds, with cloud and rain followed by cool northwest winds; but the time occupied by the trying easterly winds is proportionately larger.

It is difficult to describe or exhibit the climatic peculiarities of any region without the use of charts. Elaborate publications of this kind, for United States weather, have issued from the Weather Bureau at Washington; the Climatic Charts for the Years 1870-99 show the normal precipitation for each quarter of the year, the normal percentage of sunshine, the normal barometric pressure, reduced to sea-level, the normal temperature of the air at the surface of the earth, the mean maximum and mean minimum temperatures, the highest and lowest recorded temperatures. In addition to these, charts of first and last frost and of prevailing winds have also been published. The ordinary popular textbooks on meteorology are very largely occupied with climatology, properly so called. Of these, that by Prof. Frank Waldo (New York, 1896) is probably the most complete for America; the treatises of Angot, Traité élémentaire de météo

rologie (Paris, 1899) and Hann's Handbuch der Klimatologie (Stuttgart, 1893) are the most complete for European data. But in almost all respects, the most careful work of the kind ever published is entitled Atlas of Meteorology, vol. iii. of Bartholomew's Physical Atlas (London, 1899). In this we have a general text on climatology accompanied by about four hundred maps illustrating the climate and the weather of all parts of the globe for each month and for the whole year, and also an admirable bibliographical list of more important modern publications on this subject. A table of about forty columns of numerical data would seem to be necessary in order to present the complete idea of climate as imagined by Hann, in his great text-book on Climatology; but most of these are included in the plates and diagrams collected in Bartholomew's Physical Atlas.

Perhaps the most important feature control ling plant-life is the relative distribution of temperature and rain from month to month during the year. Climatic types have been elaborated by Harrington, Henry, and others, based upon this distribution of rain. Thus, in one region we have the prevailing summer rains; in another, the prevailing winter rains; while in still other places, the rains are divided into two seasons with dry weather between. Professor Hinrichs introduced the idea of a climatic distinction based upon the law governing the number of light and heavy rains that had fallen within a given space in a year's time. As the largest falls occurred least frequently, and so also the smallest falls, there is some intermediate rainfall that is most likely to happen. By counting up these different quantities, one obtains a series of numbers that may be represented by the equation of probabilities, and the constant term in this equation becomes the so-called 'Hinrichs Climatic Factor.'

A

The influence of climate on crops is a matter of continued investigation in the various agricultural experiment stations throughout the civilized globe, and the reader may refer to the Experiment Station Record, published regularly by the United States Department of Agriculture, for the latest information on the subject. summary of this work has led some authorities to the conclusion that cereal crops are raised successfully only by means of careful special cultivation, so that the resulting crop is not so much an evidence of the influence of climate as of the influence of human skill and husbandry in modifying and assisting climate. In the interior of continents, the clear, dry air facilitates great ranges of temperature, both diurnal and annual; the soil is dry, evaporation rapid, and delicate plants do not survive the rigors of cold and drought. On the other hand, an oceanic or insular climate is more uniform as to temperature, moisture, and cloudiness, and more favorable to the development of animals and plants. The influence of climate in disease is principally secondary in that climatic conditions affect the growth of germs, fungi, and noxious animals, through which man suffers.

There is no well-authenticated case of an appreciable change of climate within the past two thousand years. The researches of Eginitis on the climate of Greece seem to establish this principle beyond doubt. Neither is it possible that any change on the surface of the earth due to

man-such as deforestation, reforestation, agriculture, canals, railroads, or telegraph linescan have had anything more than the slightest local effect, if any, on climatic phenomena that depend upon the action of the whole atmosphere. On the other hand, it is probable that appreciable changes have taken place in the course of the very long intervals known as geological periods or æons. The phenomena of the flora, the fauna, the erosion, and the geological stratification, all agree in showing that there have been times when the Lake Region and the Saint Lawrence Valley, the Middle States and New England, were covered with ice and glaciers; a similar condition has prevailed over northwestern Europe. Such changes may have been produced by changes in the elevation of the land and distribution of the ocean, by periodic changes in latitude, by changes in the composition of the earth's atmosphere, or by changes in solar radiation. All of these are plausible causes; but at present there is no agreement of authorities as to the real cause of the changes in so-called geological climate. To these changes in the continents and the climates, we may plausibly attribute the development of a great variety of flora and fauna, the migratory habits of birds, the traditions of the early history of the human race, and the extinct plants and animals of paleontology. See EVOLUTION.

One of the most evident causes of the differences of climate is the relation of the wind to the land and ocean. When the prevailing wind is from the ocean, the land experiences moist and usually cloudy or rainy weather. This is due essentially not so much to the temperature of the water as to the mere fact that water of any temperature will evaporate largely into the air, and fill it with moisture. Thus, it is an error to say that the climate of Great Britain and western Europe is affected by the Gulf Stream, or that the climate of California and British Columbia is controlled by the Japan Current; in both these cases it is the moist ocean wind that brings cloud and rain, and the amount of this latter is not influenced in the slightest degree by the Gulf Stream or the Kuro Siwo. Another important consideration in climatology is the relation of the wind to the mountain ranges. Thus, on the windward side of a range, there is ascending air which causes damp weather with cloud or rain; whereas, on the leeward side of a mountain range there is descending air, which is always dry and clear, and frequently quite warm.

The relation of climate to physiography has been essentially a relation of cause and effect. The surface features of the land, as we now know them, present to us hills and valleys which we may easily recognize as the result of erosion by wind and water, continued for many ages, and assisted by frost and the varying hardness of the different kinds of rock and soil. These features, as we now see them, are usually all that remain after a depth of many thousands of feet of soil and rock has been broken down and carried into the sea. Geology tells us what strata and masses must, at one time, have existed; but physiography shows how all this material has been carried away by the action of the frost, wind, and rain, which constitute prom

inent features of the climate.

Among the works that treat of meteorological climate, the first place must be given to Bartholomew, Atlas, vol. iii. Meteorology (London,

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