Page:Encyclopædia Britannica, Ninth Edition, v. 22.djvu/64

 48 S I G S I G I30f HIND-SIOHT. FORE-SIGHT. Fig. 1. position about 4 feet behind the breech of the gun, holding th tiring lanyard taut ; when the object and the bead of the fore-sigh appear to be on the centre of the wire across the H of the hind- sight he fires. The forms of sights preferred by experts for accurate laying are extremely varied, and nothing but practice can determine the most suitable to individual eyesight. Where the eye can be brought close to the hind-sight, one of the best systems is that adopted for British field-guns, where a fine peep-hole constitutes the hind-sight, and the fore- sight consists of diagonal cross- wires ; the first rapid or rough adjustment of the gun is made with the aid of a V- shaped notch on the hind -sight and an acorn point on the fore -sight. Some prefer pointers for the fore-sight, either O- shaped, so that the object appears between the cusps of the O this is the French method or placed diagon- ally like cross- wires with the intersec- tion removed. Sil- vered vertical lines are preferred by many good shots. If the gun is mount- ed in a fixed posi- tion, say on a siege platform, and, if the relative positions of the target and Fig. 2. some Other object Speed-sights used in the British navy. are known, it may be found convenient to lay the gun on the target by directing the sights at the other object. This is principally done in the case of howitzers dropping shells at high elevation into a work. They fire over a pro- tecting bank and are laid by reversed sights from the muzzle backwards at a steeple, a pole, or other convenient object. To secure greater accuracy than can be attained by the eye, telescopes are resorted to. It is obviously easy to apply to a match rifle a telescope with sufficient strength to resist the jar of firing, and to provide it with the neces- sary fittings for elevation, deflexion, &c. ; but with ordnance the shock is much greater, and the telescope has to be removed before firing. This renders it difficult to secure a truly accurate attachment ; but probably the immediate future will witness a sufficiently satisfactory solution of the problem as regards guns on firm platforms. Efforts have been made from time to time to overcome the necessity for extreme accuracy due to the short bearing of the telescope by bringing the fore-sight into play; this can be done either by great powers of adjustment of focus, so as to view first the fore-sight and then the target, or by adding a half -object lens, and so getting simultaneous images of fore-sight and target. The application of electricity to the laying and firing of heavy guns has caused a remarkable development of the systems of sighting introduced recently into the forts which protect the shores of the United Kingdom. Sup- pose a battery of guns to command a channel, and that it is desired to concentrate their fire on a hostile vessel endeavouring to run past. Each detachment lays its gun both for elevation and direction in accordance with the figures which appear on a dial in the emplacement. Each dial is worked by electricity from an observing station away from the smoke and noise of the fort ; as the hostile vessel approaches the observing officer follows its course on a chart. The observing station is placed at a consider- able height above the water-line, so that a vertical base of calculation is obtained. Hence the angle of depression given by the telescope when pointing at the object indicates the range, and the direction of the telescope indicates the line of fire ; these indications are automatically corrected for the positions of the guns. In practice the officer follows the ship's course, signals to the battery the line and distance of a point a little ahead of the vessel, and receives a signal from the battery that the guns are laid and ready. He then fires electrically as the ship is coming into the ex- pected position. (EM) SIGISMUND (1362-1437), German emperor, was born on 14th February 1362. After the death of his father, the emperor Charles IV., he received the margraviate of Brandenburg ; and his betrothal with Mary, the daughter and heiress of Louis of Poland and Hungary, gave him a right to look forward to the succession in these two coun- tries. But in 1383, when Louis died, the Poles chose Hedwig, Mary's sister, as their queen ; and Sigismund was unable to marry Mary and to secure the crown of Hungary until 1387, as her rights had been seized by Charles of Durazzo, and after his death she had been made prisoner by the ban of Croatia. Sigismund was soon involved in a war with the Turks, and in order to obtain the means of carrying on the struggle he gave Brandenburg in pledge to his cousin Jobst of Moravia. Defeated at Nicopolis in 1396, Sigismund fled to Greece; and in his absence his wife died. When he returned to Hungary the people rose against him, made him prisoner, and gave the crown to Ladislaus of Naples. Sigismund escaped, and having sold the Altinark, which he had in- herited from his brother John, he was able to collect an army and to crush the Hungarian rebellion. Meanwhile his brother Wenceslaus, king of the Romans, had been deposed, and Rupert of the Palatinate was chosen as his successor. In 1410 Rupert died, and Sigismund and Jobst of Moravia were both elected to the crown. Jobst died in the following year, and then Sigismund was universally recognized as king. One of the chief events of his reign was the assembling of the council of Constance, which met for the purpose of bringing the great schism in the church to an end. Sigismund marred his services in connexion with the council by assenting to the burning of John Hus, to whom he had granted a safe conduct. For this treachery he had to pay a heavy penalty, for it led indirectly to the Husite War, which raged for about sixteen years. In 1435 peace was restored, and Sigismund obtained possession of Bohemia. In 1415 he gave Brandenburg, which had been restored to him after Jobst's death, in fief to Frederick, burgrave of Nuremberg; and in 1423, in reward for ser- vices rendered in the Husite War, Frederick, margrave of Meissen, received the duchy of Saxony with the electoral dignity. Sigismund was crowned emperor in 1433, having obtained the Italian crown two years before. He died at Znaim in Moravia on 9th December 1437. He possessed
 * onsiderable intellectual ability, but he never did full

justice to his powers, being recklessly extravagant and of a wayward and impulsive temper. See Aschbach, Geschichte Kaiser Sigismund's (1838-45) ; Schroller, Die Wahl Sigismund's zum romischen Kmilg (1875) ; Bezold, Konig Sigmund und die Reichskriege gegen die Hus-iten (1872-77) ; Kerler, Deuteche Reichstag sakten unter Kaiser Sigmund (1878). SIGISMUND, the name of three kings of Poland. See POLAND, vol. xix. pp. 290-291 and 294. SIGMARINGEN, the seat of government of the Prussian administrative division of the same name, is a small town