Part 358

Length of Pendulums to vibrate Seconds at every fifth degree of latitude.

+----------+---------+ |Degrees of|Length of| | Latitude.|Pendulum.| +----------+---------+ | | Inches.| | | 39,027 | | 5 | 39,029 | | 10 | 39,032 | | 15 | 39,036 | | 20 | 39,044 | | 25 | 39,057 | | 30 | 39,070 | | 35 | 39,084 | | 40 | 39,097 | | 45 | 39,111 | | 50 | 39,126 | | 55 | 39,142 | | 60 | 39,158 | | 65 | 39,168 | | 70 | 39,177 | | 75 | 39,185 | | 80 | 39,191 | | 85 | 39,195 | | 90 | 39,197 | +----------+---------+

Rule.--To find the length of a pendulum to make any number of vibrations, and vice versa.

Call the pendulum making 60 vibrations the standard length; then say, as the square of the given number of vibrations is to the square of 60; so is the length of the standard to the length sought. If the length of the pendulum be given and the number of vibrations it makes in a minute be required; say, as the given length, is to the standard length, so is the square of 60, its vibrations in a minute, to the square of the number required. The square root of which will be the number of vibrations made in a minute.

PENNANT, PENNON, a small flag or color.

Gentlemen PENSIONERS, (Gentilshommes Pensionnaires, Fr.) a band of gentlemen, who guard the British king’s person in his own house, and for that end wait in the presence chamber. They were first instituted by Henry VII. They are usually forty in number. Their officers are, a captain, lieutenant, standard-bearer, and clerk of the cheque. Their ordinary arms are guilt pole-axes. Their pension is 100l. per annum; they are usually called beef-eaters, from their usually fat appearance and indolent habits.

PENTACAPSULAR, having five cavities.

PENTAEDROUS, having five sides.

PENTAGON, in fortification, a figure bounded by five sides, or polygons, which form so many angles, capable of being fortified with an equal number of bastions. It also denotes a fort with five bastions.

PENTAGRAPH, (Pentagraphe, Fr.), An instrument whereby designs, &c. may be copied in any proportion, without the person, who uses it, being skilled in drawing.

PENTANGLE, A figure having five angles.

PENTANGULAR. See PENTAGON.

PENTAPOLIS, in geography, a country consisting of five cities. This name was given, particularly, to the valley wherein stood the five infamous cities destroyed by fire and brimstone in Abraham’s time. The most celebrated Pentapolis was the Pentapolis Cyrenica in Egypt, whose cities were Berenice, Arsinoe, Ptolemais, Cyrene, and Apollonia

PENTASPAST, (Pentapaste, Fr.) An engine that has five pullies.

PENTATHLON. The five exercises performed in the Grecian games, viz. leaping, running, quoiting, darting, and wrestling.

PENTHOUSE, a shed hanging forward in a sloping direction from the main wall of a place.

PEONS, Ind. municipal foot soldiers. These men are chiefly employed to assist in collecting the revenues, and carry a pike or staff. Most persons in India keep servants, who wear a belt with the master’s name. These are likewise called Peadahs.

PEOPLE, of color. Blacks, Mulattoes, so called. They form part of the British territorial army, and are distributed, in corps, among the West India islands.

PERAMBULATOR. See PEDOMETER.

PERCH, in mensuration, is ten feet long. See MEASURE.

PERCUSSION. The impression which a body makes in falling or striking upon another, or the shock of two moving bodies. It is either direct or oblique.

Direct PERCUSSION, is where the impulse is given in the direction of a right line perpendicular to the point of contact.

Oblique PERCUSSION. When it is given in the direction of a line oblique to the point of contact.

Centre of PERCUSSION. That point wherein the shock of the percutient bodies is the greatest.

PERCUTIENT, striking against or upon.

PERDU, a word adopted from the French, signifying to lie flat and closely in wait. It likewise means the forlorn hope.

A corps PERDU, Fr. Desperately.

A coup PERDU, Fr. At random.