Page:Encyclopædia Britannica, Ninth Edition, v. 17.djvu/383

Rh N E V N E V 367 breaks up into the Great Neva (850 to 1700 feet wide), the Little Neva (945 to 1365), and the Great Nevka (280 to 1205), this last, two miles farther on, sending off the Little Nevka (370 to 1129). In front of the delta are sandbanks and rocks which prevent the passage of vessels except by five narrow channels, of which the best has a depth of 7 to 20 feet. The most of its alluvial burden being deposited in the lakes, the Neva takes a long time to alter its channels or extend its delta: an accession of 1570 acres was all that was registered between 1718 and 1834. According to Destrem the current above the delta is 114,659,529 cubic feet per minute, a mass of water greater than that of the Rhone or the Rhine. The ordinary rise and fall of the river is comparatively slight, but when the west wind blows steadily for a long time, or when Lake Ladoga sends down its vast accumulations of block-ice, inunda tions of a dangerous kind occur. In 1824 and 1879 the former cause produced a rise of more than 12 feet. According to observations extending from 1703 to 1879, the mean day of the freezing of the Neva is November 25, the earliest October 28 (1805), the latest (not quite certain) January 9 (1711), and the next latest December 26 (1826). The mean day of opening is April 21, the earliest March 18 (1822), and the latest May 12 (1810). The mean number of days open is 218, the least 172 (1852), the greatest 279 (1822). NEVADA, one of the most western of the States of the American Union, was formed from a portion of the territory acquired by the United States- from Mexico by the treaty of Guadalupe Hidalgo. The boundary line commences in the centre of the Colorado river, where the 35th parallel of north latitude crosses that stream (near Fort Mojave) ; thence it runs in a direct north-westerly line to the point where the 39th parallel of north latitude intersects the 120th degree of longitude west from Greenwich (near the centre of Lake Tahoe), thence north on that meridian to the 42d parallel of latitude, thence east on that parallel to the 37th meridian west of Washington, thence south on that meridian to the Colorado river and down that stream to the place of beginning, enclosing an area of 110,700 square miles. The State is bounded on the S. and W. by California, N. by Oregon and Idaho, and E. by Utah and Arizona. At the time of the discovery of the silver mines (1858-59) what is now the State of Nevada was a part of Utah. By Act of Congress of March 2, 1861, Nevada became a Territory ; and, with a modification of its bound aries, it was admitted as a State on October 31, 1864. By the upheaval in past ages of the Eocky Mountains and the Sierra Nevada, there was enclosed an ancient sea, several hundred thousand square miles in extent. The draining off and evaporation of the waters so enclosed left an immense plateau, having a general elevation of 4000 to 6000 feet above the present sea-level. Although this table land is spoken of as a &quot;basin,&quot; yet throughout its whole extent it is traversed by ranges of mountains rising from 1000 to 8000 feet above the general surface, and having the same northward and southward trend as the Sierra Nevada and the Rocky Mountains. The surface of the country as a whole presents a very barren, rocky, and mountainous appearance, yet between the parallel ranges a?e valleys from 5 to 20 miles in width, all having about the same altitude above the sea. Where traversed by rivers or creeks these contain considerable areas of arable land, the amounts usually being proportionate to the size of the streams. They are timberless, except for a few cotton-wood trees found along the rivers. Upon the mountains the quantity of timber depends upon the altitude. The lower ranges are bare, or contain only a scanty^ growth of piiion, cedar, or mountain mahogany, of very little economic importance. Several of the higher ranges contain small bodies of valuable timber, while the eastern slope of the Sierra Nevada is well-clothed with forests of conifers, which have proved of inestimable value to the people of the State. The river system is peculiar, only two of the streams of Rivers, the State finding their way to the sea : the Owyhee, lakes, which rises in the northern part, empties into the Snake, an&amp;lt; ^ and thence passes through the Columbia river to the Pacific spnngSl Ocean ; and the Colorado river, on the southern bound ary, flows into the Gulf of California. All the other streams either sink in the sand of the interior valleys or terminate in lakes that have no outlet. The Humboldt river, about 300 miles long, empties into Humboldt Lake or &quot; Sink &quot; ; Truckee river, which drains Lakes Tahoe and Donner (in the Sierra Nevada), after a course of 125 miles, falls into Pyramid and Winnemucca Lakes. Walker river, 100 miles long, rises in the Sierra and discharges into Walker Lake; Carson river, 180 miles long, also rises in the Sierra Nevada, and empties into the &quot;Sink of the Carson&quot; or Carson Lake. Reese river rises in the Toyabe Range (within the basin region), and after a course of about 150 miles disappears in the sand; Quinn river, in the northern part of the State, after a course of 80 miles, similarly disappears in the soil; the Amargosa (bitter) river, in the southern part of the State, is 150 miles long, and, after sinking and rising several times, finally loses itself in the sands of Death Valley just over the line in California. Such of the creeks as are not tributaries of the rivers either sink in the sandy plains or end in small pools. Most of the lakes are merely sinks for the scanty streams. Of these, as already mentioned, are Humboldt, Pyramid, Winnemucca, Walker, and Carson Lakes, which, with the beautiful Lake Tahoe in the Sierra Nevada, com plete the enumeration of the bodies of water of any con siderable magnitude in the State. In many places on the sides of the mountain ranges are to be seen well-defined water-lines of the ancient sea or of extinct lakes, indicating a far greater extension of water surface and a much moister climate than at present. Hot springs, many of which have medicinal virtues, are found in all parts of Nevada. The most noted are the Steamboat Springs, in Washoe Valley, on the line of the Virginia and Truckee Railroad. The climate of Nevada is characterized primarily by its Climate extreme aridity. The air currents from the Pacific are thoroughly drained of their moisture before reaching the borders of the Great Basin, and pass over it as dry winds. In the southern part of the State, where the elevation above sea is least and the temperature highest, the rain fall averages not more than 5 inches per annum, while evaporation is extremely rapid. In the northern part the rainfall is greater, averaging not far from 15 inches in many localities. Nowhere, however, is it sufficient for the needs of agriculture, and consequently irrigation has to be universally resorted to. The mean annual temperature in the habitable portions of the State ranges from 70 Fahr. in the south to 45 in the north. This, however, expresses but a part of the conditions of temperature. The range between summer and winter, and between day and night, is very great. At several meteorological stations in the State the maximum temperature is quoted at from 100 to 111 Fahr., while the minimum temperature ranges as low as - 23 Fahr. The temperature varies greatly according to altitude. In the lower valleys snow seldom lies more than a day or two in winter. The weather in winter as a rule is dry, bright, and pleasant. In summer the nights are everywhere delightfully cool. The fauna of the State is poor, and illustrates, with Fauna the flora, the aridity of the climate. Coyotes, badgers, JJ^ and rabbits are perhaps the most abundant animals, as they certainly are the most characteristic. In the more