In Fig. 2 is given a diagram of the best of these mercury pumps, the one devised by Sprengel.
The supply of mercury is contained in the reservoir on the left. It flows over into the bulb B, where it falls in drops into the long tube on the right. These drops entrap between them the air in B. The mercury which runs out is collected and poured back into the reservoir on the left. In this manner practically all the air can be removed from the bulb B, and hence from any vessel R, which may be connected with B. At M is a manometer which indicates the pressure in the vessel R, which is being exhausted.
A pump of this type is capable of producing a vacuum in which the pressure is only 1oo,ooo,oooth of an atmosphere.
Aix-la-Chapelle (āks-lă-shä-pel'), German Aachen, a city of Prussia. It was founded by the Romans and contains the tomb of Charlemagne. Three treaties were signed here, the most important being that of 1748, when a congress was held between France, England, Holland, Austria, Spain, Sardinia and Modena. This treaty made Switzerland independent, the Rhine free to navigation, secured the Protestant succession in England, and the disunion of the French and Spanish crowns. The dislike of England and France for the treaty caused the "Seven Years' War," begining in 1755. Pop. (1910) 156,044.
A'jax was the son of Telamon, king of Salamis, and next to Achilles in warlike strength. He led the men of Salamis to Troy in twelve ships, and was called the bulwark of the Greeks. At the death of Achilles Ajax, as the bravest of the Greeks, claimed his armor, but it was given to his rival, Ulysses. Upon this, becoming insane, he killed himself. Sophocles tells the story of his madness and death in his tragedy Ajax.
Ak'bar, one of the greatest and wisest of the Mogul emperors, was born at Amarkote, in Sindh, in 1542. When he ascended the throne only a small part of what had formerly belonged to the Mogul empire owned his authority, and he devoted himself with wonderful success to the recovery of the revolted provinces. He tried by every means to encourage commerce. He had the land carefully measured, so that the taxes should be fair. His people were of different races and religions, but he was just and tolerant to all. He founded schools and was friendly to scholars. Measures like these gained for him the title of "Guardian of Mankind," and caused him to be held up as a model to Indian princes of later times. He died in 1605.
Akene (d-ken'). A seed-like fruit, as in the sunflower, dandelion, etc. Often written "achene." See Fruit.
Akenside (d'ken-sid), Mark (born 1721, died 17 70),an English physician and poet,who chiefly owes his position among the poets to his Pleasures of the Imagination, a poem which at once became famous.
Ak'ron, Ohio, a city, the ccunty seat of Summit County, and a large manufacturing, shipping and railroad center, 35 miles south of Cleveland. Incorporated in 1836, the city is on the Ohio Canal, the Pennsylvania, Erie, Baltimore & Ohio and other railroads. It has coal mines in its vicinity and large industries within it, including one of the largest printing and publishing establishments in the world, match and rubber goods factories, flour and other cereal mills, boiler and mining machinery works, besides cordage, pottery and sewer-pipe, mower a,nd reaper works, a lithographic plant, etc. Buchtell College, of the Universalist denomination, has its seat here, with 20 instructors and 300 students, while there are good public school facilities, a public library, a hospital and efficient police and fire protection. In the neighborhood, reached by train service, are a number of attractive lake resorts. Pop. (1910) about 69,067.
Alabama (al'a-bd'ma), State of (meaning "here we rest"), with its southern border on the Gulf of Mexico, is from 150 to 200 miles wide, and from 278 to 336 miles long, and is larger than New York, Pennsylvania or Virginia.
Surface. The area of the state is about 52,250 square miles. The northern end of the state is crossed by the Tennessee River, which in the west flows through a fertile terraced valley, but in the eastern section is flanked by low mountain ranges. The Allegheny range enters in the northeast, trends southwest and terminates in foot hills and sand mountains toward the center of the state. There next succeeds on the west a plateau in which are found the rich iron and coal beds for which the state is famous; on the east a Piedmont region of rolling upland, while the southern part of the state, comprising three-fifths of its area, is a broad coastal plain.
The chief rivers are the Mobile, Alabama, Tombigbee and Tennessee. The Mobile is formed by the junction of the Alabama and the Tombigbee, and after a short course of forty-five miles empties into Mobile bay.
Climate. Because of its altitude the northeastern section of the state has a delightful climate; the Piedmont region is healthful, and in the country near the coast the heat is tempered by the Gulf winds, while the low lands along the rivers are malarious.
Resources. The climate and varied soils of Alabama are favorable to the growth of a wide range of agricultural products, and previous to the discovery and development of its vast mineral wealth the products of the state were chiefly agricultural. The chief crop is cotton, grown throughout the state, but especially in the famous black
