TLA 



PLA 



>f the sea. This motion may proceed 

 from the waves that agitate the vessel, or 

 the wind acting upon the sails, which 

 makes her stoop at every blast. 



PITCH pipe, in music, an instrument 

 used by vocal practitioners to ascertain 

 the pitch of the key in which they are 

 about to sing. It is blown at one end 

 like a common flute, and being shortened 

 or lengthened by a scale, is capable of 

 producing, with great exactness, all the 

 Semitones within its compass. 



PITCH stone, in mineralogy, is of vari- 

 ous colours, as grey, green, yellow, and 

 red, in their several shades, but general- 

 ly of the paler cast. It occurs in mass. 

 Internally it is shining, with a greasy 

 lustre. Its fracture is conchoidal, passing 

 into splintery, it approaches to hornstone. 

 Its fragments are angular and sharp-edg- 

 ed. Sometimes it occurs in smooth 

 granular distinct concretions. It is hard, 

 brittle, and easily frangible, and the spe- 

 cific gravity is 2.3. It is fusible, by 

 means of the blow-pipe, into a porous 

 enamel. It is composed of 



Silica 64.58 



Alumina 15.41 



Oxide of Iron .... 5 



Loss 



8499 

 15.01 



I-JO 



This mineral occurs in mountain mas- 

 ses, and constitutes entire mountains. It 

 forms the base of a particular kind of 

 porphyry, and abounds in many parts of 

 Germany and Siberia. 



PITTOSPORUM, in botany, a genus 

 of the Pentandria Monogynia class and 

 order. Essential character : calyx de- 

 ciduous ; petals five, converging into a 

 tube ; capsule two to five valved, two to 

 five celled ; seeds covered with a pulp. 

 There are three species. 



PIVOT, a foot or shoe of iron, or other 

 metal, usually conical, or terminating in 

 Si point, whereby a body, intended to turn 

 round, bears on another fixed at rest, 

 and performs its circumvolutions. The 

 pivot usually bears or turns round in a 

 sole, or piece of iron or brass, hollowed 

 to receive it. 



PLACARD, or PL AC ART, among fo- 

 reigners, signifies a leaf or sheet of pa- 

 per, stretched out and applied on a wall 

 or post, containing edicts, regulations, 

 fee. 



PLACE, in law, where a fact was com- 



VOL. V, 



matted, is to be alleged in appeals of 

 death, indictments, &c. 



PLACE, in philosophy, a mode of 

 space, or that part of immoveable space 

 which any body possesses. Place is to 

 space or expansion, says Mr. Locke, as 

 time is to duration. Our idea of place is 

 nothing but the relative position of any 

 thing with reference to its distance from 

 some fixed and certain points. Whence 

 we say, that a thing has or has not 

 changed place, when its distance either 

 is or is not altered with respect to those 

 bodies with which we have occasion to 

 compare it. That this is so, continues 

 that great philosopher, we may easily ga- 

 ther from hence, that we have no idea of 

 the place of the universe, though we can 

 of all its parts. To say that the world is 

 somewhere, means no more than it does 

 exist ; however, the word place is some- 

 times taken to signify that space which 

 any body takes up ; and in this sense, ac- 

 cording to the same author, the universe 

 may be conceived in a place ; but he 

 thinks that this portion of infinite space 

 possessed by the material world, might 

 more properly be called extension. 



PLACE, in war, a general name for all 

 kinds of fortresses where a party may 

 defend themselves : thus, 1. A strong or 

 fortified place, is one flanked and cover- 

 ed with bastions. 2. A regular place, 

 one whose angles, sides, bastions and, 

 other parts, are equal : and this is usual- 

 ly denominated from the number of its 

 angles, as a pentagon, hexagon, &c. 3. 

 Irregular place, is one whose sides and 

 angles are unequal. 4. Place of arms, 

 is a strong city or town, pitched upon for 

 the chief magazine of an army ; or, in a 

 city or garrison, it is a large open spot of 

 ground, usually near the centre of the 

 place where the grand guard is common* 

 ly kept, and the garrison holds its ren- 

 dezvous at reviews ; and in cases of alarm 

 to receive orders from the governor. 5. 

 Place of arms of an attack, in a siege, is 

 a spacious place covered from the enemy 

 by a parapet or epaulement, where the 

 soldiers are posted ready to sustain those 

 at work in the trenches against the sol- 

 diers of the garrison. 6. Place of arms 

 particular, in a garrison, a place near 

 every bastion, where the soldiers sent 

 from the grand place to the quartets as* 

 si gned them relieve those that are either 

 upon the guard or in sight. 7. Place of 

 arms without, is a place allowed to the 

 covert way for the planting of cannon, to 

 oblige those who advance in their ap- 

 proaches to retire. 8. Place of arms in 



3 D 



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