Mortar (grinding)

“ With strong, sure strokes the three naked men shot out into the stream and past its center—seemingly unobserved. It began to look as though they would gain the other side unseen by the enemy. But suddenly, from the loop-holed section, came spiteful little squirts of fire. Against that fire only the mortar could cope—and the mortar had turned its attention elsewhere. Tiny geysers kicked themselves up where the Mauser bullets struck and skipped on the water. The roar from the Shirt-tailers rose in louder indignation, and the crew serving the mortar was feverishly refinding the range. ”

“ The center circle represents the bore, while the three outer arcs show the relative thickness of the bore wall at (1) the smallest diameter of the chase, (2) at the trunnions, and (3) at the vent. The small arc inside the bore indicates the powder chamber found in the pedrero and mortar.
Mortars (fig. 23d) (p. 038) were excellent for "putting great fear and terror in the souls of the besieged." Every night the mortars would play upon the town: "it keeps them in constant turmoil, due to the thought that some ball will fall upon their house." ”

“ If the trunnion of a gun breaks in the discharge, or a quoin flies out, the shot is materially affected; never ranging, under such circumstances, the accustomed distance, nor with its usual accuracy. Practice with mortars proves beyond dispute the necessity of a firm base for the gun, for with a much less charge they project a greater mass farther. [72] A mortar discharged on land, exceeds in range the same description of gun on board of ship, or on the best-constructed platform. ”

“ The rubble is poor, imperfectly coursed, and held together by the excellence of the mortar, or rather of the lime, for the mortar is carelessly mixed and is full of sea shells, which have been brought with the sand and left uncrushed. It is clear from appearances, both inside and outside the building, that the south-east angle has, at some period soon after its construction, fallen down, and been rebuilt soon afterwards clumsily and in haste. No mere battering by a ram, no strokes from the missiles of a catapult, however ponderous, would have brought down both turret and wall. ”

“ It was intended that one 13-inch mortar, of enormous weight, should be put upon each, that these mortars should be fired with twenty-three pounds of powder, and that the shell thrown should, at a distance of three miles, fall with absolute precision into any devoted town which the rebels might hold on the river banks. The grandeur of the idea is almost sublime. ”

“ There is also a kind of land-mortars, mounted on travelling carriages, invented by count Buckeburg, which may be elevated to any degree; whereas the British as we have already stated, are fixed to an angle of 45 degrees, and are firmly lashed with ropes.
Partridge Mortar, is a common mortar, surrounded by 13 other little mortars, bored round its circumference in the body of its metal. The centre one is loaded with a shell, and the others with grenades. The vent of the large mortar being fired, communicates its fire to the small ones; so that both shell and grenades go off at once. ”

“ The pieces are the Japanese latest type of coast-defense mortars, such as are used along the Straits of Shimoneseki and about the Bay of Yezo. They were brought by sea to Dalny, carried by railroad for a distance of fifteen miles to the end of the track, and from thence were hauled by hand over special tracks laid direct to the emplacements. In some cases, indeed, the guns were dragged on rollers through the sand, as many [27] as 800 men being required to haul a single mortar; for the mortar barrels, without the carriage, weigh eight tons apiece. ”

“ For mortars of six, eight, or ten inches diameter, the serpents should be made in one and two ounce cases, six or seven inches long, and fired by a leader, brought out of the mouth of the mortar, and turned down the outside, and the end of it covered with paper, to prevent the sparks of the other works from setting it on fire. For a six inch mortar, let the quantity of powder for firing be two ounces ”

“ Coehorn, who first proposed them in 1674—is to-day in use, of the same pattern and for the like service then suggested. Monster mortars have been constructed from time to time, in the hope of producing immense destruction in bombardments with single shells containing a large quantity of powder. The most recent of these, the monster mortar made by Mallet for the British government, weighing 114,000 pounds, with a bore of 36 inches and a shell of 2912 pounds, failed to be of any service. Perhaps the most unique mortars ever made were to be found in the island of Malta in the last century. ”

“ A cloud came into being from the explosion of a mortar shell, and two men dropped to the ground. In answer to the mortar, the flaring barrel of a tank gun spoke hoarsely, and half the crew of the mortar fell in turn. But there seemed no end to this deadly dialogue. The next moment there came the burst of a bomb from a low-flying plane, and the tank half turned over on its side, a heap of smoking steel. ”

“ The terre-plein may be placed at any convenient depth below the surface of the ground, and the revetment of the interior slope, if any be used, will not ordinarily be carried higher than the muzzle of the mortar. As the traverses are not subject to gun-fire, the splinter-proofs afforded by the central passage may be added to by building others along both sides of the traverse; and by deepening the mortar emplacement sufficiently, they may be given enough cover to make them true bomb-proofs. ”

“ The bombardments now became daily, and all our efforts at retaliation either with artillery or trench mortars proved entirely ineffectual. There was nothing we could do except clear as many men as possible away from the danger area, and come back at dusk to rebuild our parapet. Towards the end of the tour the Boche started firing rifle grenades before each mortar, so that we should stoop to avoid the former and so miss seeing the flight of the latter. ”

“ The mortar being placed upon the middle of the platform, the gunner mounts upon it, and suspends the plummet in front of the muzzle, covering the object. Where the plummet thus suspended cuts the crest of [Pg 44] the epaulment, the first stake is driven. A second stake is then driven in the same line between the mortar and the epaulment. The pointing-cord being attached to the first stake and stretched to the rear, over the point where the plummet touches the top of the mortar, determines the point on the ground at which the rear stake is driven. ”

“ If the mortar be too thick, extra labour is involved in its use, and much time wasted. If it be so thin as to run easily from the trowel, a longer time is taken in setting, and the wall is liable to settle; also there is danger that the lime or cement will be killed by the excess of water, or at least have its binding power affected. It is not advisable to carry out work when the temperature is below freezing point, but in urgent cases bricklaying may be successfully done by using unslaked lime mortar. ”

“ If a small quantity of powdered charcoal and hyper-oxymuriate of potash be rubbed together in a mortar, an explosion will be produced, and the charcoal inflamed. Three parts of this salt, and one of sulphur, rubbed together in a mortar, produce a violent detonation. If struck with a hammer on an anvil, there is an explosion like the report of a pistol. ”

“ It was of great moment to renew it, and corporal Borbidge and six carpenters commenced the work at four o’clock in the evening while the battery was still in action. A naval mortar required a ponderous arrangement of sleepers and planks to sustain it, for, with an ordinary charge of gunpowder, it has been known to make a vertical jump some six inches high and reach the stand again with a crushing jerk sufficient to shake the structure in every part. To meet concussions of such violence the platforms for sea-service mortars were invariably of the strongest kind. ”

“ The bed for the heavy ten-inch mortar is the only one which has yet [Pg 100] been adopted. The cheeks are of cast-iron, and somewhat similar in form to those in the beds of siege-mortars; but in the front, the cheeks turn up to receive between them the front transom, which has, countersunk in and bolted to it, an elevating screw-bed, through which works an inclined elevating screw, which rises or falls by turning the nut, fitted on it by means of a lever inserted into mortises cut in the direction of the radii of the circular nut. ”

“ It is well known that mortar fire is very inaccurate, except at fixed long distances, in consequence of the high angle, the slowness of flight of the projectile, the variability of the powder pressure, and the inability to change the elevation and the charge of powder rapidly. In the pneumatic gun, the complete control of the pressure remedies the most important of the mortar's defects and makes the fire accurate from long ranges down to within a few yards of the gun. ”

“ Whenever a severe mortar fire was opened upon his line of pits, he would station himself in a peculiarly exposed position on top of the [227] earth mound that protected his magazine. From that point he could direct the work of every gun under his command and at the same time do much for the protection of his men. A mortar shell can be seen in the air—particularly at night, when its flaming fuse is a torch—and its point of contact and explosion can be calculated with a good deal of precision. ”

“ Direction of fire may be secured at night with mortars by nailing or screwing two boards to the platform outside of the cheeks, and the elevation by drawing a line across one of the trunnions, or by inserting a wedge-shaped block of the proper inclination below the mortar and the front transom or step. Night-firing with guns should be limited to a small number of rounds, as it consumes ammunition to little advantage. ”

“ A six-celled destructor kiln burns about 42 tons of refuse in twenty-four hours, leaving about one-fourth of its bulk of clinkers and ashes. The clinkers are withdrawn from the furnaces five times each day and night, or about every two-and-a-half hours, into iron barrows, and wheeled outside the shed which covers the destructor, and when cold are wheeled back to the mortar mills, of which there are two at each depot, each having a revolving pan 8 feet in diameter, with 27-cwt. rollers, the pan making twenty two revolutions a minute. ”

“ A large or even a small stone descending from a considerable height, under such circumstances, would be sure, if it fell in a boat, to go through its bottom, causing it to fill at once, and would be equally fatal if falling upon the heads or bodies of human beings. The rock, which is of the nature already described, admitted of being easily hewn into such shape as was desired, while exposure to the atmosphere soon hardened it to the required consistency and resisting power. A second discharge of such a mortar might possibly involve as much danger to the defenders as to the enemy. ”

“ A mortar is always fixed at a certain angle, and of course you fix a howitzer the same way when you use it for that purpose. With a mortar the amount of powder of a given strength required to send a shell to a given distance is known to every artillery-man, but with a howitzer one must get it by experiment. ”

“ Against them our mortar fire was as ineffective as against the works, and what was to be looked for from guns provided only with round shot and case? Case would not carry one-sixth of the range, and round shot against handfuls of men, scattered here and there, were as worthless as shell. The difficulty was still unsolved when Captain Mercier, 39th Regiment, suggested firing the 5.5-inch shell of the royal mortars, with short fuzes, from the 24-pounder guns which had the same calibre as the mortars, 5.8-inch. ”

“ We entered by the new breach, and had soon reason to be satisfied that the pinnace had wholly escaped from injury, and that the fire was entirely extinguished. The mortar, however, and pieces of the chain, had been driven forcibly into the opposite side of the inclosure. Having now every reason to be satisfied and tranquil, I explained to the boys the nature of a cracker, the manner of its operation, and the important service for which I was indebted to the old mortar. ”

“ The mortar is placed in a hole, dug in the ground, a few inches left standing out; the earth is shovelled in, and driven down firm; a penthouse lid, to keep out rain, dirt, and insects, renders it complete. Amateurs require nothing of this kind. A small mortar may be a tube, open at both ends, and fitted with a wooden bottom, to which it is to be firmly screwed. Fig. 94 represents such mortar: it may be 4 diameters high; and the foot should have a conical hole turned in it to receive the cone fastened to the shell. ”

“ The practice of our masons of putting the blood of oxen into mortar was no doubt in the first instance associated with the idea of a sacrifice; however this may be, the blood had no doubt a real effect in hardening the mortar, just the same as treacle, which has been known to be used in our days. The use of cement when any extra strength is needed has put aside the use of either blood or treacle in the mixing of mortar. ”