Broken Period, a term used in the returns and financial statements of the British army, when the regular distribution of pay is interrupted, or the effective force is lessened by the absence of one or more individuals, or by any other cause. A correct and faithful statement of broken periods is essentially necessary in every well regulated regiment, as not only the service but the public purse may be materially injured by the neglect, or embezzlement of individuals. Adjutants and pay-masters cannot be too scrupulously minute on this important head.
PERIPHERY, the circumference—as of a circle.
PERISTYLE, a circular range of pillars for the support or ornament of any building, &c. used in the ancient amphitheatres.
PERKERNUCKA, Ind. Petty officers are so called in India.
PERMANENT Fortification, is defined to be the art of fortifying towns, &c. so as to resist the attacks of an enemy, that makes regular approaches.
PERMANENT rank, a rank in the army, which does not cease with any particular service, or locality of circumstances; in opposition to local or temporary rank. See [Rank].
PERPENDICULAR, (Perpendiculaire, Fr.) According to Vauban’s system, it is a line raised in a perpendicular direction on the centre of the exterior side of any given polygon. In mean fortification, which prevails more than any other system, the perpendicular contains 30 toises in the exagon, and in polygons that have a greater number of sides; but it contains fewer when the polygons have a less number. The perpendicular is used by this engineer to determine the other lines and angles belonging to a fortification. In proportion as the perpendicular is increased, the extent of the flanks is augmented.
Perpendicular fortification, is that in which all the component parts flank each other at straight angles. Pagan, and other engineers, made the flanks perpendicular to the lines of defence. This is also the denomination of the improved system of Montalembert, which has superceded in a great measure all others; the distinction between this and the old, would require a treatise to exemplify it.
Perpendicular, (Perpendiculaire, Fr.) When any star is vertical, it is said, in astronomy, to be perpendicular, because its beams fall directly upon us.
Perpendicular, in geometry, when any right line is perpendicular to all the lines it meets with in a plane, it is said to be perpendicular to that plane.