PRO 



592 



PRO 



PRISMAT'IC SQVARB or COMPASS. An 

 instrument used in surveying, for mea 

 suring horizontal angles only, and which 

 are taken from the magnetic meridia 

 a graduated float-card being attached to 

 the needle. 



PRIS'MOID, from vgiff/Aat, a prism, and 

 t.Sos, like. The frustrum of a wedge : a 

 solid which has two rectangular faces 

 and the remaining faces trapezoids, ter- 

 minating with their parallel edges in the 

 same lines as the two parallel faces, which 

 are called ends, the greater being the base. 



PRIS'ONS, MAMERTINE. Certain fearful 

 places of confinement in ancient Rome, 

 intended chiefly for state prisoners. 



PRI v ATE'ER. A ship of war, owned and 

 equipped by a private man or men, at his 

 or their expense, to seize or plunder the 

 ships of an enemy in war. Such ship 

 must, however, be licensed or commis- 

 sioned by government, otherwise it is a 

 pirate. 



PRIV'ATTVE, from privo, to bereave. 1. 

 That of which the essence is the absence 



of something : darkness is a privative. 



2. In grammar, a prefix to a word, which 

 changes its signification, and gives it a 

 contrary sense, as wn in unwise. The pri- 

 vative is, however, sometimes a suffix, 

 as less. 



PRIV'IIEGE. A -writ of privilege is one 

 to deliver a privileged person from cus- 

 tody, when arrested in a civil suit. 



PRIV'T, Fr. privie, private. In law, a 

 partaker : a person having a private 

 interest in any action. 



PRIV'T CHAMB'ER, Gentlemen of the. 

 Officers of the king's household. 



PRIV'T-COCNCIL. An extensive body, 

 with whose advice and assistance the 

 crown administers the government. Privy 

 Counsellors are made by nomination of 

 the crown, without patent or grant. 



PRIV'Y-SEAL. A seal affixed by the 

 sovereign, or the lord keeper of the privy 

 seal, called also Privy-Seal from his office, 

 to instruments which are afterwards to 

 pass the great seal. 



PRO and CON. Pro et contra. For and 

 against. 



PRO'A. Flying Proa. A description of 

 vessel, used in the South Seas, with the 

 head and stern exactly alike, but with 

 the sides differently formed: that which 

 is intended for the lee side being flat, the 

 other rounded. It is fitted with an out- 

 rigger, on the windward side, to prevent 

 its upsetting. 



PROAU'LIOX, jrja and otv\y, hall. In 

 architecture, the same as Vestibule, which 

 tee. 



PHOB'ABILITT. 1. In the doctrine of 

 chances, the ratio of the number of chances 

 by whi:h the event may happen, to the 

 numbc? by which it may both happen 



and fail , so that if there be constituted 

 a fraction, of which the numerator is 

 the number of chances for the events 

 happening, and the denominator the 

 number for both happening and failing, 

 the fraction will properly express the 

 value of the probability of the events 



happening. 2. Probabilities is used 



synonymously with chances: we thus 

 speak of the science of probabilities, and 

 the doctrine of chances. 



PROB'ABILISM. In theology, a theory 

 according to which it is lawful to follbw 

 a probable opinion in doubtful points, 

 even though others may appear to be 

 more probable. 



PKO'BANG. A flexible piece of whale- 

 bone, with an oval piece of ivory or piece 

 of sponge fixed to the end ; used by sur- 

 geons to push down into the stomach 

 foreign bodies which stick in the oeso- 

 phagus. 



PRO'BATE, Lat. probatus, from probo, to 

 prove. 1. In law, the probate of a will is 

 the proving of its genuineness or validity, 

 or the exhibition of the will to the proper 

 officer, with the witnesses, if necessary, 

 and the process of determining its va- 

 lidity and the registry of it, and such other 

 proceedings as the laws prescribe as pre- 

 liminary to the execution of it by the 



executor. 2. The right or jurisdiction 



of proving wills, which in England belongs 

 to the spiritual courts. 



PROBE, Germ, probe, proof. A surgeon's 

 instrument, of a long and slender form, 

 for examining the depth or other circum- 

 stances of a wound, ulcer, or cavity, or 

 the direction of a sinus, and the like. 



PROBE SCIS'SORS. Scissors used to open 

 wounds, the blade of which, to be thrust 

 into the orifice, has a button at the end. 



PROB'LEM. H^XY^O.. A question 

 proposed. 1. In logic, a proposition that 

 appears neither absolutely true nor false, 

 and consequently may be asserted either 

 "n the affirmative or negative ; or, gene- 

 rally, any question involving doubt or un- 

 certainty, and requiring some operation, 

 experiment, or further evidence, for its 

 solution. 2. In mathematics, a proposi- 

 tion in which some operation is required. 



PROBO-CIDIA'NA. Proboscidians. A fa- 



ily of mammiferous animals, of the order 

 Pachydermata, characterised by a cylin- 

 drical trunk or proboscis, composed of se- 

 veral thousands of small muscles, variously 



terlaced, extremely flexible, endowed 

 with the most exquisite sensibility, and 

 terminated by an appendage resembling 

 a finger. The elephant is the only living 



PROBOS'CIS. TI^offxi;,from^o, before, 

 and jSco-xiu, to feed. The lengthened tube, 

 snout, or trunk belonging to the Probosci- 

 dians. See PROBOSCIDIAN*. 



