Piston
in machinery, a device so fitted as to occupy the sectional area of a tube and be capable of reciprocaannals and tion by pressure on either of its sides. , CAIUS, It may be of any shape corresponding to restrain accurately to the bore of the tube; but the cylindrical form is almost exclu- . Piso, sively employed for both, as in the common pump and the steam engine. One , in which of its sides is fitted to a rod, to which cruelty, it either imparts reciprocatory motion, as Germani- in the steam engine, or by which it is itself reciprocated, as in the pump. In he destroyed himthe former case, it has no opening ing leading from one side to the other, and is termed solid, though generally not really so; but in the latter, an aperture controlled by a valve permits the passage of the fluid from one side to the other during its downward movement; except in force pumps. A distinction is made in pumps; the solid piston being known as a plunger; the hollow piston as a bucket. The piston usually requires packing to cause it to fit closely within its cylinder and at the same time allow its free backward and forward movement.
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Pit Villages
collections of earth caves dug in the ground and covered with stones, wooden or wattle lids, or clay or sods of turf. They were used by prehistoric races or by races at the The pits lowest stages of barbarism. are oval or pear-shaped, varying between 22 and 42 feet in length and from five feet high.
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Pita Flax
flax made from the fiber of the Agave Americana (called also and used for twine, rope, and maguey), hammock meshes, etc. In Mexico it is also used for oakum. Labillardière for found that its strength is to that of common flax as 7 to 114.
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Pitcairn
a borough of Pennsylvania, in Allegheny co. It is about 15 miles E. of Pittsburgh on the Pennsylvania railroad. There railroad are shops and yards, machine shops and foundries, and electrical supply works. There are important coal mines in the neighborhood. Pop. (1910) 4,975; (1920) 5,738.
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Pitch
in music the character of a sound which is dependent on the frequency of the vibrations of the sounding body. The standard pitch adopted by scientists is that of a tone produced by a string vibrating 256 times per second for lower C, or 512 vibrations for upper C, being the eighth and ninth powers respectively of 2. Musicians have, however, decided that better and more brilliant effects are produced by sharpening to a concert pitch, which, for upper C, is placed in England at 538 vibrations per second; in France, at 522; and in Germany, at 528. See Sound
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Pitch
pich, a dark, sticky product obtained by drying out tar, and from the residue of turpentine distillation. It is made in tar-producing countres. It is used chiefly in calking ships, in protecting submerged woodwork, and, to some extent, in medicine, as in white-pine tar compounds for colds. A pitchy black night is a synonym for utter darkness. See Tar ; Turpentine
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Pitch Blende
a mineral chiefly found in Saxony and Cornwall, composed of 86.5 oxide of uranium, 2.5 black oxide or iron, galena, and silex. In color it from brown to black, and occurs 1912. varies fro globular, reniform, massive, disseminated, and pulverulent. Sp. gr. 7.5. It generally accompanies uranite. Radium is extracted from it.
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Pitman (BENN an American phonographer)
BENN, an American phonographer, born in Trowbridge, England, July 24, 1822; brother of Sir Isaac Pitman, the inventor of phonography; was educated in his brother's academy; lectured and taught phonography throughout Great Britain for 10 years. He came to the United States in 1853, and founded the Phonographic Institute in Cincinnati; invented the electro-process of relief engraving in 1856; was military recorder of State trials during the Civil War. His works include "Manual war. of Phonography"; "History of Shorthand"; and "Phonographic Dictionary." He died in 1910.
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Pitman (SIR ISAAC an English born)
SIR ISAAC, an English born in Trowbridge, Engstenographer; ; 4, 1813. He was master of land, Jan. an. the British School of Barton-on-Humber in 1831, established the school at Wottonunder-Edge in 1836 and removed to Bath in 1839. He was the inventor of the phonetic system of short-hand writing and published his first treatise on the entitled " Stenographic Soundhand," in 1837; "Phonography" (8th , 1840); and " Phonographic Re- Companion " ( 1853). He was head of the Phonetic institute at and was identified with the spellreform. He was knighted in 1894, died Jan. 22, 1897.
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Pitman, Isaac
Isaac (1813-1897), the English inventor of modern shorthand. He was a native of Wiltshire and was educated in London. In 1832 he became master of a school in Barton-on-Humber. Five years later he published his Stenographic Sound Hand, the basis of modern stenography. He also founded the Phonographic Journal, afterward known as the Phonetic Journal. One of his last contributions was a complete manual, known as The Shorthand Instructor for Commercial Schools. He was identified with a movement for the simplification of spelling, and is credited with having suggested to the British government the present method of collecting postage in the form of stamps instead of money. A brother, Benn Pitman, established a school of shorthand at Cincinnati in 1853.
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Pitney
MAHLON, a Justice of the States Supreme Court. Born at Morristown, N. J., 1858, and graduated Princeton in the class of '79. Afclass that date he practiced law at Mor- , and from 1895-1899 ser served in as a Republican representative. From 1901 to 1908 he was associate justice of the Supreme Court of New Jersey, and in 1909 became Chancellor of the State. President Taft appointed Pitney to the Supreme Court, Mar. 13, &
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Pitt
WILLIAM. See CHATHAM.
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Pitt
WILLIAM, an English statesman; born in Hayes, England, May 28, 1759; second son of the Earl of Chatham; was educated at Cambridge University; studied law and was elected to Parliament in 1780. He was as strongly opposed to the American War as was his WILLIAM PITT father. In 1783 he became me prime min ister; was active in the negotiations of peace with the United States, and was instrumental in the passage of many important measures. Retiring in 1801, he was recalled to office when the Peace of Amiens was broken and war with Napoleon again brought on. Throug public career he was noted as a parliamentary leader and orator. He died in Putney, England, Jan. 23, 1806.
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