statistics giving the weight of a cubic foot of aqueous vapor of different percentages of saturation and at various temperatures at the level of the sea. At 32° F. a cubic foot of aqueous vapor ranges from 211 grains with 10 per cent saturation to 2.113 grains with 100 per cent saturation. At 68° F. a cubic foot of aqueous vapor ranges from .748 grains with 10 per cent saturation to 7.480 grains with 100 per cent saturation. At 100° F. a cubic foot of aqueous vapor ranges from 1.977 grains with 10 per cent saturation to 19.766 grains with 100 per cent saturation. At 110° F. a cubic foot of aqueous vapor ranges from 2.611 grains with 10 per cent saturation to 26.112 grains with 100 per cent saturation. Vapor is saturated, when it is at the point of condensation and evaporation goes on as long as there is any deficit below 100 per cent of such saturation. From the foregoing meteorological compilation, it will appear that the point of saturation and weight of aqueous vapors per cubic foot vary greatly at different temperatures. The matter under this sub-title is involved in the problems of WATER SUPPLY and will receive further consideration under that title in a succeeding volume of this encyclopedia.

Hu

Controlling Factors in Rainfall.-At sealevel in the tropics over such large bodies of water as the Indian Ocean, the amount of aqueous vapor moving vertically upward may exceed the quantity in a column of air over the Arabian and Sahara deserts. Still the vapor contents of the air over Siberian and Lybian deserts average nearly as much as that of the air over Vienna and Paris. The heat prevents its condensation. Were it cooled, it would produce normal rainfall. Humidity is the amount of aqueous vapor in the atmosphere, as compared with the amount of such aqueous vapor in it, when the atmosphere at a given temperature is 100 per cent saturated. midity, therefore, is relative and in some zones and localities it varies inversely, as the temperature, especially where there may be a lack of moisture as there is east of the Rocky Mountains and over the desert regions of the earth. When water is vaporized, pressure is exerted on atmospheric gases. Thus both vertical or convective currents may be generated, clouds may be formed and heavy rainfall may ensue, as a result of the cooling of the saturated water vapor in the upper strata of the atmosphere. The heat, liberated in the cooling process, retards the condensation and checks the rainfall. A rising barometer indicates the absence of vapor pressure, the expansion of dry air, slight evaporation and no rainfall. Humidity, temperature, topography and the physical phenomena already mentioned are factors more or less controlling, in the problem of rainfall over a given territory. There are others, such as the contour of the territory, its elevation above the level of the sea, the extent of its forests, the configuration of its mountains, the influence of continents upon humidity and character of its seasons. Notwithstanding the complexity of the phenomena, conditioning rainfall or precipitation, the same has been observed over long periods and reduced to mean annual tabulations. There have also been deduced formulæ to ascertain the presence and amount of evaporation, which, to slight extent only,

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indicates the amount of rainfall or precipitation, for the former may be both a contributing cause and one of the results of the latter. Dalton, Bigelow, Russell, Meyer and others have proposed evaporation formulæ to determine evaporation under various conditions of humidity, temperature, wind velocity, vapor tension and barometric pressure. The results obtained from the application of such formulæ are not identical, nor do they always conform to actual measurements, which are difficult to make.

The United States Weather Bureau and the climatological stations of some other nations have compiled statistical tables of evaporation over various land and inland water areas, but not over oceans, seas and gulls, which altogether cover three-fourths of the surface of the earth. From all such bodies of water evaporation is continuous and the greatest. These great fountains of the deep supply the vapor-laden clouds, which are swept landward and release their waters in refreshing rains, wintry snows or in some other form of precipitation. Frequently such vapor-bearing clouds are swept against mountain ranges, as those rising from the Mediterranean Sea are swept against the Alps and those rising from the Pacific Ocean against the Andes Mountains. In some regions precipitation is much greater than it is in others, and over the same region it varies greatly in different years. That is due to the operation and effect of the physical conditions already stated. However, over cycles of years it is quite uniform, as will hereinafter appear. Deforestation decreases and reforestation increases the general average. Forests promote rainfall, retard evaporation and run off and store up precipitation in pools, ponds and lakes, some of which are the sources of streams and rivers. The United States and many other nations have bureaus, or departments devoted to scientific forestry, one of the most important and necessary functions of government, if the habitable areas of the earth are to be preserved. Deforestation and consequent lack of rainfall have rendered many once populous areas now uninhabitable, as indicated in this article. This and other generations ought not to neglect a matter of such vital importance to themselves and to succeeding generations, but ought to enter upon the systematic reforestation of all properly available areas.

Regional Precipitation. The amount of precipitation, over many portions of the habitable earth, has been observed for long periods substantially as follows: In the polar regions there is no rainfall. Precipitation there is congealed in snow and icy particles. In the tropics there is little snow except on the highest mountains and most precipitation is in the form of rain. In the upper latitudes of the temperate zones there are both rain and snow. Over the Sahara, Arabia and other desert regions and in the desert regions in Australia and South America there is but little precipitation, while along windward coastal regions the annual precipitation is abundant, as found along the Atlantic and other continental coasts facing eastward. Usually those sides of mountain ranges that face oceans, or large bodies of water, have a much larger rainfall than do the opposite sides, which face inland areas. There

is more rainfall on the slopes of the Sierra and Coast ranges where many glacial lakes and ponds exist in the ranges themselves, such as Tahoe, Clear Lake and others, than there is rainfall on their eastern slopes. East of some of these and of the Rocky Mountains the annual precipitation is light and large desert areas had existed, but for irrigation. No one law has been deduced from all these varied phenomena, affecting precipitation over all parts of the habitable globe to determine its amount. Much data has been collated from actual measurements. Some of these will indicate the amount of precipitation in those regions and at various altitudes.

E. S. Bellasis, sometime engineer of the Public Work in India, in substance stated that "the rainfall in India varied from 2 or 3 inches in Scinde to 450 inches at Cherrapunji in the eastern Himalayas and that at two stations in the Bombay hills, only 10 miles apart, the annual rainfall were respectively 300 inches and 50 inches and that in England at Hemstanton, it was about 20 inches, while at Seathwaite it was about 200 inches." He stated that "the annual rainfall at Mercara in South India was 119 inches, in King William's Town in Cape Colony 27 inches, at Melbury Moor, in England 50.7 inches, at Newport in the Isle of Wight 32 inches, in the basin of the Cataract River in New South Wales from 33.7 inches, in 1896, to 56.4 inches, in 1898 in the basin of the Nepean River in New South Wales 44.3 inches and in 1905 in the valley of Sudbury, Mass., 42.3 inches."

The water supply of a country is largely conditioned upon its water resources and the latter are dependent to a large extent upon its rainfall, or rather precipitation, which includes rain, hail, sleet and snow. The amount of annual precipitation over a given territory in successive years is not constant, nor is it uniformly distributed, except over a few such States as Wisconsin and Michigan, and over some foreign limited districts.

The annual precipitation in the State of Washington ranges from 12 to 120 inches in different localities, though in Seattle for a period of 19 years it averaged 38.8 inches. In different parts of Oregon it ranged from 8 to 138 inches and in Texas from 9.3 inches at Pasco to 48.2 inches at Houston. Nor is the annual precipitation over a locality constant from year to year. The Weather Bureau's report shows that the precipitation at Dodge City, Kan., has ranged from 9.9 to 33.7 inches. There are dry and wet years as there are dry and wet seasons. In the drought of 1894 and 1895, the deficiency in precipitation measured in the upper Mississippi Valley from 7.8 to 12 inches, in New England from 5.3 to 8.1 inches and in the south Pacific watershed from 4.4 to 4.6 inches. In three months of 1905, there was an excess of 2 inches in the rainfall at Yuma over its mean annual precipitation. In 1900, the rainfall at Bay Saint Louis, Miss., was 101.5 inches which was an excess of about 50 inches over normal precipitation for the State. The difference between the maximum and minimum rainfall on the Croton watershed (New York) in a period of 43 years was 26.8 inches and in Pittsburgh (Pa.) that difference was 25.3 inches in a period of 71 years.

Mean Annual Precipitation in the United States and Canada.- The United States maintains several hundred observation stations in addition to those maintained by the States themselves and by individual and corporate enterprise, where meteorological and climatological observations are made and for half a century have been made and records kept of the annual precipitation at those stations. From all such official and authentic observations and the computations made therefrom, climatological tables have been compiled, showing in most cases over periods of years the mean annual precipitation at scores of stations in the United States. Foreign countries have made similar observations and records. In nearly all of the tables, the measurements are the resultant of many observations and are denominated "the mean annual precipitation."

From such official and from other well-authenticated measurements, the writer has selected some and averaged others from approved records to ascertain and state the mean annual precipitation over the United States and Canada. The following represent the mean annual precipitation over the localities mentioned, or they are aggregated from a number of stations over large areas, showing such precipitation. Many of these are from the reports of the United States Weather Bureau, extending over a number of years and others from authentic data. The mean annual precipitation in the coastal region of Alaska varies from 60 to 110 inches.

United States. The greatest annual precipitation in the United States is over the western slopes of the mountains forming the Continental Divide which intercept the vapor-laden clouds from the Pacific and precipitate their moisture in some localities to an average of 70 to 135 inches.

ALABAMA. The United States Weather Bureau gives the mean annual precipitation, as measured at 15 stations, as 52 inches, at Montgomery it is 50.8 inches and at Mobile 62.1 inches.

ARIZONA.-Along the Colorado it is less than 3 inches, at Phoenix 7.4 inches, at Fort Grant 15 inches and at Flagstaff 22 inches.

ARKANSAS. It averages 46.7 inches, being 49.6 inches at Little Rock, 55.2 inches at Helena and 41.8 inches at Fort Smith.

CALIFORNIA. It ranges from 32.2 inches over the Sacramento watershed to 10.2 inches at San Diego. Professor Meyer states that it averaged 9.6 inches at San Diego for a period of 65 years. At Berkeley it is 26.47 inches, at San Francisco 23 inches and at Los Angeles 17.6 inches.

COLORADO. It is variable. At Denver it is 14.7 inches, at Pueblo 11.6 inches, at Orchard 17 inches and at Long's Peak 16.7 inches. In other sections it varies from 7.01 to 26 inches and over Colorado River watershed it is 17.7 inches.

CONNECTICUT.- At Hartford it was 44.50 inches, at New Haven 47.2 inches, at New London 48.08 inches and at Waterbury 49.9 inches.

DELAWARE. At Millsboro it was 47.3 inches. FLORIDA. There is annual precipitation over the State as determined at 13 stations of 54.53 inches. At Tampa it is 53.1 inches, at Key West 37.9 inches, at Miami 58.3 inches and at Jacksonville 53.4.

GEORGIA. The United States Weather Bureau reported in 1906 that the annual precipitation in the northeastern part of the State was 54.1 inches, in middle Georgia 49 inches, in southeastern Georgia 50.7 inches, at Atlanta, for a period of years, it averaged 49.2 inches, at Savannah 48.67 inches and at Clayton 68.5 inches.

IDAHO. It varies from 6.3 to 40.4 inches, but in most sections it ranges from 12 to 13 inches.

ILLINOIS. It averages 36.5 inches. At Chicago for 40 years it averaged 33.5 inches. At Springfield it is 37.4 inches and at Cairo 41.6 inches.

INDIANA. The mean annual precipitation over the State is 38.4 inches. At South Bend it is 34.5 inches, at Indianapolis 41.9 inches and at Marion 37 inches.

IOWA. From the measurements at 46 stations scattered over the State, the United States Weather Bureau reported the mean annual precipitation over the State to be 31.5 inches, at Keokuk it was 35.1 inches and at Sioux City 25.8 inches, at Iowa City in 1890, it was 58 inches.

KANSAS. Measured at 19 stations, it averaged 27.3 inches, at Garden City it was 19.6 inches, at Wichita 30.4 inches, at Atchison 37.1 inches and at Topeka 34.1 inches.

KENTUCKY.At 10 stations it ranged from 42.5 inches at Lexington to 50.3 inches at Wibblesboro. At Louisville it is 44.5 inches.

LOUISIANA. There is great variation in the yearly rainfall. In New Orleans the annual rainfall has been as low as 31 inches and as high as 85.6 inches. For 67 years it averaged 56.1 inches. It ranges there from 55.4 to 62.6 inches and over the State from 46 inches over the southern stations to 55 inches over the eastern.

MAINE-At Portland it was 42.8 inches, at Lewiston 46.2 inches, at Eastport 43.4 inches, at Bar Harbor 48.9 inches, at Mayfield 52 inches.

MARYLAND and DELAWARE.-The annual precipitation ranges from about 44 inches in the former to 47.3 inches in the latter. At Baltimore it was 43.4 inches, at Washington and District of Columbia 43.1 inches, in the valley of the Potomac 35.28 inches. Other unofficial records give annual precipitation at Baltimore as 40.7 inches, at Washington as 40.7 inches and in the District of Columbia at 38.77 inches.

MASSACHUSETTS.— At Boston it ranged from 43.7 to 45.3 inches, at New Bedford from 46.4 to 47.9 inches, at Blue Hill Meteorological Observatory 47.2 inches, at Williamstown 39.41 inches, at Lawrence 43.1 inches, at Fitchburg 45.4 inches, at Amherst 46.3 inches, at Nantucket 36.5 inches, over the Wachusett watershed 47.1 inches and over the Sudbury watershed 45.3 inches.

MICHIGAN. It averages 32.91 inches and is similarly distributed. At Detroit it has averaged 32.1 inches over a period of 40 years.

MINNESOTA. It averages 26 inches, while at Duluth it is 29.5 inches, at Saint Paul 28.68 inches, over the Crow Wing Valley 30.81 inches and over Croix Valley 32.58 inches. Professor Meyer gives the mean annual rainfall at Saint Paul for a period of 78 years at 27.3 inches.

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MISSISSIPPI. The mean annual precipitation is about 50 inches. In the Yazoo Valley it is 48 inches, at Natches 50 inches and at Vicksburg 53.8 inches. Over the Tombigbee watershed for a period of 50 years it has averaged 49.2 inches.

MISSOURI. It ranges from 34 inches in the northwestern counties to 46 inches in the southeastern counties. It averages 39.9 inches at Saint Louis. The general average over the State is 39 inches.

MONTANA. It ranges from 11.8 to 18.5 inches. At Kipp it is 18.5 inches, at Glendive 15.9 inches, at Butte 12.2 inches and at Great Falls on the Missouri 13.4 inches and at Havre 13.5 inches.

NEBRASKA-As determined at 6 to 12 stations it averaged 23.5 inches and was principally in rain. At Omaha it was 30.8 inches, at Lincoln 27.7 inches and at North Platte 17.9 inches.

NEVADA. It ranges from 10.8 inches at Carson City to 11.2 inches at Pioche, but varies in most parts of the State from 3 to 12 inches. At Reno it measures 7.52 inches.

NEW HAMPSHIRE.-At Bethlehem it was 37.7 inches, at Plymouth 42.4 inches, at Concord and at Keene 40.4 inches and at Nashua 43 inches.

NEW JERSEY.-The annual precipitation is 47.7 inches over the State. At Dover it is 51.2 inches, at Asbury Park 48.1 inches and at Atlantic City 42 inches. Over the Pequannock watershed it is 50.1 inches and over the Hackensack River 46.15 inches.

NEW MEXICO.- It varies from 7.2 to 15.8 inches, though there it has had a precipitation of 25 inches. At Sante Fe' it is 14.2 inches. There is slight snowfall, though the State's highest peaks in the north are snow-capped much of the time, and those snows are its principal sources of water supply. Similar conditions prevail in some of the Rocky Mountain States, affording their principal water supply.

NEW YORK. The mean annual precipitation at the United States Weather Bureau stations over the State for 25 years averaged 39.26 inches. Over Suffolk County it averages 45 inches. Over Long Island for 67 years it has averaged 42.56 inches, at New York City 42.87 inches, over the lower Hudson 44.93 inches, at the Croton Dam from 44.93 to 50.38 inches, over the Esopus watershed 46.6 inches, at Oxford 45.4 inches, at Albany 34.84 inches, at Little Falls 54 inches, at Utica 42.29 inches, at Binghamton 36.98 inches, at Elmira 33.23 inches, at Mount Hope 27.77 inches, at Ithaca 33.97 inches, at Cortland 44.7 inches, at Rochester 33.61 inches, at Buffalo 36.71 inches, at Oswego 36.57 inches, at Ogdensburgh 30.7 inches, at North Lake 55.7 inches and over northeastern New York 38.97 inches. Over the Taconic quadrangle it is 42 inches.

NORTH CAROLINA. The resultant of measurements at 23 stations was 52 inches. In the western counties occasionally it ranges from 70 to 100 inches, thereby becoming known as a region of extraordinary rainfall.

NORTH DAKOTA.- The mean annual precipitation is from 17 to 18 inches over the State. At Bismark it is 18.8 inches. High winds blow away much of the snows of winter.

OHIO.- This State has an annual precipitation of 38.4 inches, varying from 30.8 inches at Toledo to 42.1 inches at Marietta. At Ports

mouth it averages 41.1 inches. Over the Ohio River during a long period it varies from 32.07 to 45.79 inches and over the Muskingum watershed it averages 40 inches. At Cleveland it is 35.6 inches, at Columbus 37.2 inches and at Cincinnati from 38.4 to 45 inches. Professor Meyer states that it averaged there 40.7 inches for a period of 80 years.

OKLAHOMA.—It was computed by the United States Weather Bureau from the measurements of 10 stations and found to average 31.7 inches, with great variations in succeeding seasons and different years.

OREGON. It ranges from 8 to 138 inches and at Portland it ranges from 45.9 to 78.2 inches. At Astoria it is 77.2 inches.

PENNSYLVANIA.- The resultant of the measurements of 16 stations is approximately 44 inches. At Erie it is 39.2 inches, at Pittsburgh 36.4 inches, at Harrisburgh 38.1 inches, at York 41.9 inches, at Mauch Chunk 50.5 inches and at Philadelphia 40.6 inches.

RHODE ISLAND.- At Providence it was 44.6 inches, but by the records for 79 years it averaged 45 inches. At Narragansett Pier it was 47.4 inches and at Rock Island 45.3 inches.

SOUTH CAROLINA. It was estimated from measurements at 12 stations to be 49 inches. Monthly rainfalls in some localities and years have equalled 12 inches for a short period.

SOUTH DAKOTA.- It averages 20.3 inches, but only 1 to 2 inches fall in the form of snow. TENNESSEE. It averages over the State as measured at 18 stations about 50 inches, including 8 inches of snow. At Nashville it is 48.5 inches, at Memphis 50.8 and at Chattanooga 51.6 inches.

TEXAS.- The mean annual precipitation averages 30.9 inches over the entire State as determined at 19 stations, varying from 9.3 inches at Pasco to 48.2 inches at Houston. At Port Davis for 46 years it was 18 inches. At El Paso for 36 years it averaged 9.6 inches.

UTAH. It averages 11 inches, ranging from 6.1 inches at Saint George to 16.2 inches at Salt Lake, which is mostly snow.

VERMONT.- At Burlington 33.3 inches, at Rutland 36.54 inches, at Saint Johnsbury 35.6 inches, at Northfield 33.1 inches, at Woodstock 37.3 inches and at Jacksonville 50.3 inches.

VIRGINIA. It averaged from the measurements of 15 stations from 39.4 inches at Warsaw and Blacksbury to 50.5 inches at Big Stone Gap. At Rutland it measured 43.6 inches, at Fort Republic 38.77 inches, at Roanoke 39.09 inches and at Norfolk 50 inches.

WASHINGTON.- In the northwestern part it ranges from 12 to 120 inches, and between the Olympics and Cascade mountains it ranges from 25 to 60 inches. At Seattle for 19 years it averaged 38.8 inches.

WEST VIRGINIA.- There are 14 stations distributed over the State and the average of their measurements is 42.48 inches. Over the high plateaus the annual precipitation ranges from 45 to 50 inches, while over the lower levels along some rivers it ranges from 35 to 40 inches. Over the Greenbriar it is 44.48 inches.

WISCONSIN. The mean annual precipitation is 31.5 inches and is uniformly distributed over the State; at Milwaukee it is 31 inches.

WYOMING. It averages 13 inches, ranging

from 8 inches in some places to 20 inches in the Yellowstone Park.

Along the Appalachian altitudes from New York to the Gulf of Mexico there is a greater precipitation than there is at lower levels along the Atlantic Coast. From the United States Weather Bureau reports of the mean annual precipitation, measured at several stations in each New England State over a period of years, it appears that it averaged in Maine 44.6 inches, in New Hampshire 40.6 inches, in Vermont 38.2 inches, in Massachusetts 44.6 inches, in Rhode Island 49 inches and in Connecticut 47.2 inches.

Canada.-In Canada it varies in the western, central and eastern provinces as it does in the United States. At Victoria it averaged 37.77 inches, at Port Simpson 94.63 inches, at Regina 9.03 inches, at Prince Albert 14.45 inches, at Winnepeg 19.53 inches, at Port Arthur 23.58 inches, at Toronto 33.94 inches, in Quebec 28.76 to 41.5 inches, in New Brunswick 32.6 inches with 97.5 inches of snow, in Nova Scotia 39.6 inches and 77.5 inches of snow.

Latin America. In other countries of the western hemisphere records of precipitation are meagre. However, the unofficial reports indicate that the annual precipitation is abundant for the water supply of all the principal cities whether or not they be located on lakes, rivers and other fresh waters. In Mexico, at Vera Cruz, it measured 183 inches as maximum rainfall. In Central America precipitation varies greatly in different sections. Rainfall in the latter ranges from 50 to 200 inches annually. In Cuba at Havana it ranges from 40 to 80 inches. There is a great variation of precipitation in South America owing to its physical formation with the lofty Andes extending along its entire western border and their many lateral ranges, its high arid plateaus and swampy regions, its vast area extending from 12° north latitude across the equator to 55° south latitude and from 35° to 82° west longitude, its tropical heat over most of it and its wintry climate in some other localities and its general location with reference to the Caribbean Sea, the Atlantic and Pacific oceans. The climate is as variable as all such physical conditions can produce. Generally speaking, the precipitation is not only abundant for its water supply in most of its coastal regions, but over some areas it is excessive. Over its interior elevated districts it is slight and great desert regions exist in Brazil, Bolivia, Peru, Argentina and Patagonia, where there is but little precipitation. The annual precipitation at Bogotá is 44 inches, along the coast 73 inches, at Carácas from 24 to 34 inches, at Valdivia 108 to 115 inches, in Uruguay 43 inches, in Argentina from 2 to 63 inches and in Patagonia from 19 to 97 inches. In many parts of Brazil there is heavy rainfall and in other mountain sections there are heavy snowstorms. At Rio de Janeiro it is from 43 to 59 inches, at Blumenau 53 inches and at Ceará 60 inches. The precipitation is abundant in most of the Western States, where high mountains intercept the vapor-laden winds from the Pacific. There are many large lakes high above sea-level, one of them being Lake Titicaca, with an area of 5,000 square miles, 12,545 feet above the sea. It falls in rain and snow and not only waters vast areas but supplies the headwaters of the Amazon and other great rivers.

Europe. In Europe a few measurements will illustrate the mean annual precipitation. In England the annual precipitation varies from 25 inches or less at the mouth of the Thames to 60 inches in the lake district and in a part of Wales, while in other districts it is 40 inches. In the western counties of England near high hills it ranges from 80 to 150 inches, while in other sections it averages from 30 to 45 inches. In the eastern counties it ranges from 20 to 28 inches. The mean annual rainfall on the Vyrnwy watershed is 65.16 inches. At Litton in Bristol watershed for 58 years it averaged 41.1 inches and at Bristol 30.9 inches. Over the Thames area for 21 years it averaged 26.9 inches. Over Derwent Valley it varies from 35 inches in the south to 61 inches in the north. Over the Sheffield waterworks catchment areas precipitation averaged about 47 inches. The average rainfall over the whole of England is about 30 inches.

In the west of Scotland it ranges from 39.37 to 100 inches while in the eastern counties it is only 26 inches. At Ben Nevis it is 151 inches. Over Edinburgh district waterworks for 6 years precipitation averaged about 48 inches. Over the headwaters of the Usk, Wye and Towy rivers in Wales rainfall ranges from 45 to 75 inches per annum. In Ireland there is heavy precipitation near the high hills in the west though less than in the Highlands of Scotland. Its general average is more than it is in the eastern districts of England. Over the valley of the river Vartry the annual rainfall averages 48.82 inches. In Norway the annual precipitation varies from 12 inches at Dovre Fjeld to 83 inches between Bukken Fjord and Nordfjord. At Bergen it ranges from 73 to 89 inches. In Sweden the annual rainfall ranges from 12.32 inches at Karesuando to 45.82 inches at Cattegat. In Denmark the annual precipitation ranges from 21.58 to 27.87 inches. In Holland it averages 27.99 inches. At Utrecht it is 27.5 inches and at Tilburg it is 27.6 inches. At Amsterdam and The Hague it averages 27 inches. In Belgium the precipitation is approximately 28 inches. At Brussels it is 27.6 inches. The annual precipitation in France averages about 32 inches. For many years it averaged at Marseilles 20.75 inches and at Nantes 35 inches. Over the Rhone it ranges from 20 to 63 inches, averaging 36.32 inches. Over the Meuse it is 28.33 inches, over Yonne 30.80 inches, and over the Seine 22.7 inches. In the south of France precipitation is less than it is along the Atlantic Coast. In Switzerland the annual precipitation has been 21.7 inches, at Sierre, 32.7 inches, at Geneva, 36.6 inches, at Berne, 42.6 inches, at Montreux, 48.7 inches, on the great Saint Bernard, 65.4 inches, at Lugano, 87.3 inches, on San Bernardino Pass, 89.7 inches of rain and snow in the Alps, facing north or south, thereby intercepting vaporladen winds from the Arctic Ocean or from the Mediterranean Sea. In the valley of the Inn River it ranges from 22.43 to 57 inches. Scores of glaciers are found in the great elevated valleys of the Alps, and these feed the Rhine, the Rhone, the Po and the Inn rivers and their tributaries. The snows and glaciers cover the high ranges and intervening valleys, whose uplift resembles the foaming billowy ocean. At Saint Maria in the Alps the precipi

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tation is 104.35 inches. In Germany it ranges from 20 to 34 inches. At Berlin it is 22.8 inches. Over the Moselle it is 29.48 inches, over the Rhine 36.69 inches, over the Main from 16 to 27.44 inches and over the Oder 24.60 inches. For 10 years it averaged 47.1 inches over the Mangfall Valley near Muhlthal. In Austria the annual precipitation ranges in various sections from 20.24 to 60 inches, and on the Dalmatian Coast it has been as high as 177 inches. At Vienna for 34 years it averaged 23.42 inches. In Hungary it averages 24 inches, at Budapest 34.32 inches, at Zagrab 70.39 inches, at Fiume and over the mouth of the Danube it is 35.12 inches. In Russia, where there are many mountains, high plateaus and extensive plains facing the Arctic Ocean, there is precipitation in the form of much snow, but not extensive rainfall. The average rainfall in Archangel is 16.2 inches, in Helsingfors, Finland, 19.6 inches, in Petrograd 18.3 inches, in Dorpat 24.9 inches, in Moscow 23 inches, in Warsaw, Russia, 22.8 inches, in Odessa 15.6 inches, at Batum 93 inches, at Sochi 80 inches, in Poti 64.9 inches; while in Astrakhan it is only 5.7 inches and over the plains of Russia but 20 inches. In Portugal, whose westerly coast is exposed to the winds of the Atlantic, there are heavy fogs and precipitation in the north occasionally amounts to 192 inches, while in the interior and in the south there is far less rainfall. In Spain rainfall averages at Madrid 15 inches, at Salamanca 11.3 inches, at San Fernando 30 inches, at Bilboa 46 inches, at San Diego 66 inches, at Oviedo 74 inches and over large areas there is but little precipitation and intense heat. Italy has moderate precipitation. The Alps in the north and its Apennines, extending nearly its entire length, intercept the vapor-laden winds of the Mediterranean and Adriatic seas. It projects southerly into warm latitudes and has a hot summer climate. Over it in the classic ages Jupiter Pluvius reigned from sea to sea. Precipitation varies from 36 inches in the north to 20 inches in the south of Italy. In Sicily it averages 15 inches. Sunny Italy is characteristic of its central and southern sections, where there is infrequent and scanty rainfall in summer months. Over the Po the rainfall ranges from 30 to 48 inches and snow in the north and mists along the coast are not uncommon. The precipitation at Tolmezzo is 96 inches. In Lombardy precipitation averages 22 inches, and irrigation canals are necessary to supply the lands with sufficient water for agricultural purposes. Nearly all Italian cities are supplied with water from rivers and mountain or ground sources. Aqueducts and infiltration tunnels through tufa without linings have long been in use to maintain such supplies. Through such tunnels 22 gallons per second are delivered at Mazzara and 40 gallons per second at Zappulla in Sicily.

Dr. Angot calculated the rainfall by months at Rome and found the annual precipitation there to be 12.03 inches and at Milan to be 12.01 inches. In Greece the annual precipitation ranges from 16.1 inches in Attica to 53.34 inches in the Ionian Isles. Olympian Zeus presided over atmospheric changes and his chief weapon was the thunderbolt. The Grecian states are well watered. In Bulgaria the mean annual precipitation is 29.59 inches. In Rumania rainfall ranges from 15 to 20 inches. The water