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ing that they might endanger his professional standing, he withdrew the edition from the market very soon after its publication. The same year appeared his "Visit to 13 Asylums for the Insane in Europe." In 1848 he published the "History, Description, and Statistics of the Bloomingdale Asylum." After his return from his second European tour, he published in the "American Journal of Insanity" a series of articles on institutions for the insane in Germany and Austria, which were subsequently collected in a volume. Another series of articles on " Bloodletting in Mental Disorders " was also published in book form in 1854. His other contributions to the medical and psychological journals are very numerous. -THOMAS, a writer on law, brother of the preceding, born in Leicester, Mass., April 21, 1791, died in Philadelphia, July 14, 1849. His early education was obtained at the academy of his native town. In 1817 he removed to Philadelphia, and engaged in mercantile pursuits for a few years, and then having studied law commenced the practice of the profession in that city, where he was distinguished not only for legal ability, but for the large amount of time he bestowed without fee or reward in defending the cause of the poor, often refusing cases offering large pecuniary emolument in order to attend to those who were unable to pay. He edited in succession the "Columbian Observer," "Standard," "Pennsylvanian," and "Mechanics' Free Press and Reform Advocate;" and he took an active part in calling a convention to revise the constitution of Pennsylvania in 1837, was a prominent member of it, and is believed to have made the original draft of the new constitution. At this time he was so popular that any office in the gift of the people was at his command, but he lost the support of the party with which he was connected (the democratic) by advocating the extension of the right of suffrage to negroes. In 1840 he was the candidate of the liberty party for the vice-presidency. After that period he mingled little in political affairs, and devoted himself almost entirely to literary pursuits. His first published work was an "Essay on Penal Law," written while he was a member of the law academy of Philadelphia, and published by the library company. This was followed by an "Essay on the Rights of States to alter and annul their Charters," a work which elicited the approbation of Thomas Jefferson; a "Treatise on Railroads and Internal Communications," published in 1830; a spelling book for schools, which was highly approved by eminent teachers in Philadelphia and vicinity; a "Life of Benjamin Lundy," an eminent philanthropist. At the time of his death he had nearly completed a history of the French revolution and a translation of Sismondi's "Italian Republics."

EARLY, a S. W. co of Ga., bordering on Ala., bounded W. by the Chattahoochee river, and N. by Colamoka creek; area, 864 sq. m.; pop. in 1852, 8,641, of whom 4,211 were slaves.

The surface is a fertile plain, watered by Spring creek and several of its branches, and occupied by corn and cotton plantations, interspersed with forests of oak and yellow pine. Scarcely a rock is to be seen in the county. The Chattahoochee is navigable along the border of the county by steamboats, and the smaller streams furnish good water power. On the bank of Colamoka creek is one of those remarkable ancient mounds which have been found in various parts of the United States. It is 75 feet high, with a level surface on the top 240 by 90 feet in extent. The productions of the county in 1850 amounted to 4,354 bales of cotton, 223,037 bushels of Indian corn, and 76,377 of sweet potatoes. There were 16 churches, 1 newspaper office, and 144 pupils attending academies and schools. Value of real estate in 1856, $994,031. Named in honor of Peter Early, governor of Georgia in 1813. Capital, Blakely.

EARLY, JOHN, a bishop of the Methodist Episcopal church south, born in Virginia in 1785. At an early age he joined the Virginia conference, and became an itinerant minister. He filled successively the offices of secretary of conference, presiding elder, and delegate of the general conference. At the general conference of 1846 he was elected general book agent, in which office he continued until elected bishop in 1854. As a traveller, revivalist, and systematic preacher, it is said of him that he has few equals in the ministry of the southern Methodist church.

EARTH, the planet upon which we live. (For its motions and its relations to the heavenly bodies, see ASTRONOMY.) The ancients, familiar with only a small portion of its surface, entertained the crudest notions of its form and extent. In the time of Homer it was regarded as a flat circle, everywhere surrounded by a dark and mysterious ocean. The nations which dwelt upon its borders were called Cimmerians and described as living in perpetual darkness. In every direction the most distant lands heard of were placed on the margin of this ocean, so that as geographical knowledge increased its shores in like manner receded. The strait at the pillars of Hercules, leading into the ocean, was for many centuries the boundary of the earth toward the west. The Black sea appears for a time to have been the boundary in the other direction, and Colchis on the margin of the Eastern sea. Ethiopia reached the sea to the south. and the Riphaan mountains stretched to the northern verge of the earth. The ancient Hebrews found the same boundary to the west; but in other directions they vaguely spoke of the "ends of the earth." Availing themselves of the commercial enterprise of the Phoenicians, they had in the time of Solomon prosecuted their trading voyages through the straits of Babelmandeb into the Indian ocean, bringing home from expeditions of 3 years' duration the products of tropical regions; while their ships sent westward toward the Atlantic returned laden with the tin, silver, lead, and other metallic products of Spain and Great Britain. The ex

peditions of Alexander into Asia opened new countries in the east, and largely extended the geography of the Greeks. The Romans by their conquests added discoveries in the other direction; but these, while they removed further off, still served to fix the encircling ocean, the mare tenebrosum, as the impassable barrier and limit to the land. At a very early period the astronomers among the Egyptians, Chaldeans, and Greeks perceived that the heavenly bodies, while occupying the same positions, stood in different relations to different points upon the surface of the earth. In the school of Thales, Anaximander, Anaximenes, and Pythagoras, the sun dial was employed to mark the progress of the sun in its meridional range, and to determine the latitude of places, and the division of the year into 365 days. The length of the longest and shortest days at numerous places was determined by the Egyptians with this instrument, and they first added 51 days to the older division of the year into 360 days. Thales (born at Miletus, 640 B. C.) perceived the error of giving to the earth a plane surface, and ascribed to it a spherical figure and a position at the centre of the universe. Anaximander believed it was cylindrical; and in the Pythagorean cosmography the extraordinary advance was made of placing the sun in the centre of the system with the earth moving about it. But this step was soon lost, and the knowledge of the extent and form of the earth made but slow progress as the limited observations of travellers were gradually accumulated. A latitude observation is recorded of Meton and Euctemon at Athens, 432 B. C. As commercial intercourse was extended among the nations and navigation became an important art, the spherical figure of the earth must have become apparent by the same phenomena which are now commonly appealed to in proof of it, viz.: the sinking of distant objects seen upon a level plain, as the sea below the horizon; the greater or less elevation of the circumpolar stars, as the observer is further toward the north or the south; the different angles under which the sun is seen at noon of the same day at different points on the same meridian; and other appearances of the same character. This form being recognized, it was natural to seek the measure of its circumference, and it is extremely probable that attempts of this kind were made before any of those of which we have account. Some of the measures of the most remote antiquity appear to have relation to the terrestrial circumference; and, as stated by Laplace, they seem "to indicate not only that this length was very exactly known at a very ancient period, but that it has also served as the base of a complete system of measures, the vestiges of which have been found in Asia and Egypt." Aristotle states that before his time the circumference had been determined by mathematicians at 400,000 stadia. Eratosthenes, who lived the next century after Aristotle, appears to have been the first to clearly perceive the true method of applying astronomical observations to the measurement

of a degree upon the surface of the earth, and from this to calculate the whole circumference. At Syene, in upper Egypt, was a well, at the bottom of which the full disk of the sun was seen at noon of the day of the summer solstice; at the same time from Alexandria, then taken to be on the same meridian, its angular distance from the zenith was 7° 12'. This was the measure of the celestial arc between the two zeniths, and bore the same relation to the whole circumference as the distance between the two points on the surface bore to the circumference of the earth. Presuming this distance to be 5,000 stadia, and 7° 12′ being of a circle, the total circumference was then 250,000 stadia. The world known by the reports of travellers extended only about 38,000 stadia in a N. and S. direction; and from the pillars of Hercules to the city of Thinæ upon the eastern ocean, along his base line drawn E. and W. across the Mediterranean, Eratosthenes reckoned a greatly exaggerated distance of 70,000 stadia, and yet less than of the whole circumference. He indulges only conjectures whether the remainder was occupied entirely by the ocean he called the Atlantic, or consisted in part of strange continents and islands. Posidonius next attempted a similar measurement by observations of the altitude of the star Canopus, when seen on the meridian at Rhodes, and again at Alexandria. Finding a difference of altitude of 7° 30′, and assuming the meridional distance of the two points to be 5,000 stadia, he made the whole circumference 240,000 stadia. Of the real value of the stadium employed we are entirely ignorant; and it is certain that it was not, as employed at that time, a fixed determinate measure. The great astronomer Hipparchus of Rhodes, born at Nice, in Bithynia, 140 B. C., first determined the longitudes of places upon the earth by the eclipses of the moon, and produced maps upon which localities were designated by their latitudes and longitudes. Thus a means was furnished of determining the relative positions of places without the necessity of measurements upon the surface between them; and afterward, when suitable instruments should be contrived, of finding directly any spot beyond the sea, and returning to the starting point. Adopting these principles, Ptolemy, the astronomer and geographer, prepared the most complete map of the world so far as it was known, designating places by their latitudes and longitudes, and causing the meridians to approach each other toward the pole. For want of accurate measurement of the length of a degree, his map, however, was very imperfect. Still it continued for many centuries to be the great authority in geography; and it was not until 1635, when the difference of longitude between Marseilles and Aleppo was found to be only 30° in place of 45°, as represented upon the map, it became apparent that more perfect observations for longitudes must be adopted than those of the ancients. The uncertainty of the results obtained by observing eclipses of the moon was soon perceived, and at

last the suggestion of Galileo was adopted of observing the eclipses of the satellites of Jupiter. In the 9th century an attempt was made by direction of the caliph Al Mamun, who reigned at Bagdad from 813 to 833, to determine the length of a degree of latitude. His mathematicians assembled on the plain of Shinar, and, taking the altitude of the polar star, separated in two parties, travelling in opposite directions till they found a difference of altitude of one degree. They made the distance upon the surface the same as that given by Ptolemy, probably adopting his conclusion, which they were set to verify. From this time to the middle of the 16th century no further attention was given to ascertaining the dimensions and true figure of the earth by astronomical observations; but vast accessions of geographical knowledge were made by the enterprise of the navigators of this period. They at last solved the mystery of the mare tenebrosum. The next attempt to determine the circumference was made by Fernel, a French physician, who died in 1558. In the want of exact surveys, by which the true distance between places might be known, he measured the space between Paris and Amiens by the number of revolutions of his carriage wheel, and making his observations for latitude he made the length of a degree 57,070 French toises; a remarkably close approximation to the actual length. Willebrord Snell, a mathematical teacher of Holland, made in 1617 a similar attempt between Alkmaar and Bergen-op-Zoom; and he was the first to apply a system of triangulation to expedite his geodetic measurements. His instrument for observing angles was a quadrant of 5 feet radius. As afterward corrected by Muschenbroek, the length was 57,033 toises. In 1635 Norwood in England repeated the experiment, measuring along the road the distance between London and York, making the degree 367,176 feet, or 57,800 toises. Toward the close of the same century Picard first applied the telescope attached to a quadrant, and furnished with cross wires, to observe the angles for his triangulation, and twice measured between Amiens and Malvoisine with wooden perches a base of 5,663 toises, or nearly 7 m. in length, employing also at the other extremity a base of verification of 3,902 toises. The celestial arc of 1° 22′ 55′′ was measured by a sector of 10 feet radius. He made the degree 57,060 toises, a result very nearly accurate, attained by a fortunate compensation of errors in his method and in his standard of measure. In 1718 the second Cassini published a work upon the magnitude and figure of the earth, with an account of measurements further north and south on Picard's line made by La Hire and himself. About the time of Picard's observations the question began to be agitated, whether the form of the earth was really that of a true sphere. The tendency of the centrifugal force of bodies revolving upon their axis, established by Huyghens and Newton, must evidently be to throw their movable particles from the poles toward

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the equator and there accumulate them in a belt, increasing the equatorial diameter. Newton calculated that to maintain the hydrostatic equilibrium the proportion of the polar to the equatorial diameter must be as 230 to 231. Richer, who was sent by the academy of sciences of Paris to Cayenne in 1672, observed that the pendulum which vibrated seconds in Paris lost about 2 minutes daily at Cayenne. This fact, as Newton explained in his Principia, must be a consequence of the reduction of the force of gravity, either by effect of the centrifugal force or of increased distance from the centre. The deductions of Newton and Huyghens that the earth was a spheroid like that already observed of Jupiter, flattened at the poles, conflicting with the opposite conclusions of the first Cassini, induced the academy of sciences to cause exact measurements of meridional arcs to be made both near the equator and the polar circle. The celebrated commission of their members left Paris in 1735, Bouguer, La Condamine, and Godin to join in Peru the officers appointed by Spain, Antonio d'Ulloa and Jorge Juan; and Maupertuis with 4 others to proceed to the gulf of Bothnia, where they were joined by the Swedish astronomer Celsius. Ten years were spent by the party in Peru in the measurement of an arc of over 3° in length, extending from lat. 2′ 3′′ N. to 3° 4' 32" S. In 2 measurements of the original base the difference was hardly 24 inches; and a second base of 5,259 toises differed when measured less than a toise from its length as calculated from the triangles. The length of the degree at the equator, reduced to the level of the sea, was calculated by Bouguer at 56,753 toises, or 362,912 feet; by La Condamine, at 56,749 toises; and by Ulloa, at 56,768 toises. The northern party found a place for their operations between Tornea in Lapland and the mountain of Kittis, 57′ 29.6" further north, in lat. 66° 48′ 22′′. The difference of latitude being determined, they measured a base line upon the frozen rivers, 2 measurements giving a difference of only about 4 inches. The arc being then determined, it was found to give 57,422 toises to the degree. With this result they returned to France, being absent only 16 months. The greater length of the degrees as they approach the poles was thus established, and consequently the greater equatorial than polar diameter of the earth. Multiplied measurements in different parts of the earth now became important to determine its true figure. They have been made in various countries, and confirm the general conclusions of Huyghens and Newton. La Caille's measurement at the cape of Good Hope in 1751, the only one in the southern hemisphere, presented anomalies, or showed great irregularity in the figure of the earth, which were not explained till, nearly a century afterward, the arc was remeasured with great care under the auspices of the British government, and it was shown that the discrepancy was owing principally to the deviation of the plumb