Paradis, Fr. that part of a harbor in which vessels may ride with the greatest safety.
PARALLELES, Fr. Parallel lines in fortification are so called. See [Parallels].
PARALLELS, at a siege, the trenches or lines made parallel to the defence of the place besieged: they are also called lines of communication, and boyeaus.
Parallels, or places of arms, are deep trenches 15 or 18 feet wide, joining the several attacks together. They serve to place the guard of the trenches in readiness to support the workmen when attacked. There are usually three in an attack; the first, about 300 toises, or 600 yards, from the covert-way: the 2d and 3d, nearer to the glacis.
PARALLELEPIPED, (Parallelepipede, Fr.) one of the regular bodies of solids, comprehended under six rectangular and parallel surfaces, the opposite ones whereof are equal.
Tirer une Parallele, Fr. verbatim, to draw a parallel. To make a direct communication between one trench and another.
PARALLELISM, the situation or quality whereby any thing is denominated parallel.
PARALLELISM of a march. In order to preserve the parallelism of a march in the movement of troops each battalion must be kept perpendicular to the direction it marches upon, the whole of the several battalions in one straight line, and their several marching directions parallel to each other. The first battalion or line becomes the regulating one, and must be regarded as infallible; and from the moment that its direction is ascertained, the commander of each other, and their directing serjeants, are to consider their movements as subordinate to it, and to conform accordingly. It is the helm which guides the line, and must not change cadence; nor will it increase or diminish its speed, but from unavoidable necessity, and by particular order.
The instant communication of the word march is particularly important, that the advanced guides of the whole may step off together, and thereby maintain their line parallel to the one they quitted, and which becomes the principal guide for their battalions; each preserves its six paces from its advanced guide; this distance is to be kept by, and depends on, the replacing officer next to the color, who covers the directing guide; and if these trained guides do step equally, and in parallel directions to each other, they must be dressed themselves in line, and of consequence the centres of their following battalions.
Parallelism and distance to be observed in the formation and movement of any considerable body of troops. It is laid down as a general maxim, that no considerable body should ever be formed without a proportion of it being placed in reserve or in second line, and more or less according to circumstances. The movements of such second line will always correspond with those of the first, and it will always preserve its parallelism and distance.