equipment are (1) the buoyancy of the piers can be proportioned to the weight of traffic and to the roughness of the water; (2) owing to the special design of the bows, boats and rafts are easy to row, while the pontoons in bridge oppose little resistance to the current, and so require less anchor power; (3) transport rafts, pier heads and flying bridges can be constructed with great ease, owing to the flush gunwales on which baulks can rest if necessary; (4) the pontoon sections are convenient to handle, easy to ship or to transport by rail, and can readily be replaced singly if damaged in bridge. A canoe pontoon and superstructure adapted for pack transport has also been adopted from designs by Colonel (Sir) Elliott Wood, C.B., R.E. The pontoon consists of four sections laced together, each section being a framework of wood covered with waterproof sheeting. Three pontoons and eight composite planks form a “unit,” from which can be constructed 48 ft. of bridge for infantry in file, 84 ft. for infantry in single file, or a raft to carry 15 men or an empty wagon.
For the British army in India the standard pontoon for many years was the Pasley; it was seldom used, however, for boats could almost always be procured on the spot in sufficient numbers whereever a floating bridge had to be constructed. Later an equipment was prepared for the Indian army of demi-pontoons, similar to the Blood pontoon cut in half, and therefore more mobile; each has a bow and a square stern, and they are joined at the stems when required to form a “pier”; they are fitted with movable covers and can therefore be used in much rougher water than pontoons of the home pattern, and their power of support and breadth of roadway are the same. The Chitral Relief Expedition of 1895, however, revealed certain defects. The shape of the bow was unsuited to rapid currents; the balance was not satisfactory, and the copper sheathing cracked. Experiments were then undertaken with the bipartite pontoon.
The india-rubber pontoon does not appear to have been generally employed even in America, where it was invented. The engineer officers with the army of the Potomac, after full experience of the india-rubber pontoon and countless other inventions of American genius, adopted the French equipment, which they found “most excellent, useful and reliable for all military purposes.” The Russians, in crossing the Danube in their war with Turkey in 1878, employed the Austrian equipment. Aluminium pontoons have been tried in Germany, but have not been adopted. For light bridging work the Berthon and other collapsible boats have been adopted in Germany and Great Britain, especially for cavalry work in advance of the army. The German folding boat is made of wood framework and canvas skin; two boats are easily carried on one “folding-boat wagon.” The total length of the three sections together is 21 ft. 6 in. The British field troop R.E., attached to cavalry, carries two collapsible boats 18 ft. 6 in. long.
The methods of constructing pontoon bridges have been simplified of late years in most armies, and are usually restricted to (1) adding pontoons one by one to the head of the bridge; (2) connecting rafts of two or more pontoons into bridge by intermediate bays of superstructure; and (3) swinging across the river a bridge previously prepared alongside the shore. The formation of a bridge from rafts touching one another consumes an excessive amount of equipment, and opposes unnecessary resistance to the stream; it is therefore being discarded in most armies. “Booming out” the bridge bay by bay from the shore until the head reaches the opposite bank is unsuited for rapid currents, and is almost obsolete except for light infantry bridges.
In every army the pontoon service is in the hands of technical specialists.[1] But there are many other forms of military bridging, in which the specialist only supervises the work of the ordinary soldier, or indeed, takes no part whatever. Troops of all arms are expected to be familiar with certain methods of rough temporary bridging. In the British service the forms of temporary timber bridge usually employed are called trestle, lock and floating. The trestle bridge in its various forms consists of a series of two-legged or three-legged trestles carrying the road-bearers and chesses which form the roadway. Trestles can be improvised, but some are carried, ready for use, by mobile engineer units and they are frequently combined with pontoon bridges at the shore ends, where holding ground for the feet of the trestles is found. Lock bridges never touch water, forming single spans over a chasm. These consist of spars made into frames of which the feet rest in the banks of the river and the heads are interlocked, the whole being securely lashed. Another type of frame-bridge is the cantilever, which has been used in Indian frontier expeditions to bridge swift steep-banked streams. Improvised suspension bridges are also used. Floating bridges are made not only of pontoons but also of boats of all sorts, casks lashed together, and rafts. They are almost always combined with one or two bays of trestle bridging at the shore ends.
The organization of bridging personnel in different armies shows as much divergence of opinion as the design of pontoon equipment. In Great Britain, since the divisional reorganization, the bridging trains have been assigned to the “army troops,” which include two “bridging trains,” totalling 14 officers and 454 men with 92 vehicles, most of them six-horsed. Each train carries 32 pontoons and 32 bays of superstructure, as well as 16 trestles and 8 bays of the appropriate superstructure, and can construct 200 yds. of medium bridge in all. Besides these trains the divisional engineer units (2 field companies per division) bear with them in all 4 pontoons and 4 trestles, with the necessary bays of superstructure, their total bridging capacity being about 40 yds. of medium bridge. In France each army corps has a bridging train which admits of the construction of bridges to the extent of about 120 yds. of medium and 140 yds. of light bridging and bears besides 2 “advanced guard” trains which can provide 33 yds. of medium bridging each. Besides the corps trains there are also “army” trains, five in all, which can furnish 280 yds. of medium bridging apiece. These would be allotted in accordance with the requirements of particular campaigns. In Germany the increasing importance attached to independent cavalry operations has led to the assignment of a folding-boat wagon to every cavalry regiment. The regimental equipment provides for a ferry, capable of taking 25 to 30 infantrymen, one artillery vehicle or four horses at one journey, a foot-bridge 22 to 35 yds. in length, or a light bridge of 8 to 13 yds. By assembling the material of a whole cavalry division of 6 regiments, a foot-bridge of 110 to 210 yds. or a light bridge of 57 to 70 yds. can be constructed. The corps bridging train of a German army corps can construct 140 yds. of medium or 170 yds. of light bridging, and each of the two divisional trains, 40 yds. of medium and 148 yds. of light bridging.
PONTOPPIDAN, ERIK (1698-1764), Danish author, was born at Aarhus on the 24th of August 1698. He studied divinity at the university of Copenhagen, and for some time acted as a travelling tutor. In 1735 he became one of the chaplains of the king. In 1738 he was made professor extraordinary of theology at Copenhagen, and in 1745 bishop of Bergen, Norway, where he died on the 20th of December 1764.
His principal works are: Theatrum Daniae veteris et modernae (4to, 1730), a description of the geography, natural history, antiquities, &c., of Denmark; Gesta et vestigia danorum extra Daniam (3 vols. 8vo, 1740), a laborious but uncritical work; Annales ecclesiae danicae (3 vols., 1741-1747); Marmora danica selectiora (2 vols. fol., 1739-1741); Glossarium norvegicum (1749); Det förste forsög Norges naturlige historie (4to, 1752-1754); Eng. trans., Natural History of Norway (2 vols., 1755), containing curious accounts, often referred to, of the Kraaken, sea-serpent, and the like; Origines hafnienses (1760); Menoza (3 vols., 1742-1743), a religious novel. His Danske Atlas (7 vols. 4to), an historical and topographical account of Denmark, was mostly posthumous.
See an article by S. M. Gjellerup in Danish Biografisk Lexikon (vol, xiii., 1899).
PONTOPPIDAN, HENRIK (1857-), Danish author, son of a pastor, was born at Fredericia on the 24th of July 1857. He studied physics and mathematics at the university of Copenhagen, and when he was eighteen he travelled on foot through Germany and Switzerland. His novels show an intimate acquaintance with peasant life and character, the earlier ones showing clear evidence of the influence of Kjelland. An excellent example of his work is in the trilogy dealing with the history of Emanuel Hansted, a theorizing radical parson who marries a peasant wife. These three stories, Muld (“Soil,” 1891), Det Forjaettede Land (“The Promised Land,” 1892), and Dommens Dag (1895) are marked by fine discrimination and great narrative power. Among his other works are Fra Hytterne (1887), Folkelivsskildringer (2 parts, 1888-1890), and Skyer (1890). He began in 1898 a new series in Lykke Per, the story of a typical Jutlander.
See an article of Niels Möller in Dansk Biografisk Lexikon (vol. xiii., 1899).
PONTORMO, JACOPO DA (1494-1557), whose family name was Carucci, Italian painter of the Florentine school, was born at Pantormo in 1494, son of a painter of ordinary ability, was apprenticed to Leonardo da Vinci, and afterwards took lessons from Piero di Cosimo. At the age of eighteen he became a
- ↑ In Germany, however, as mentioned below, light bridging material has been placed in the hands of the cavalry. This tendency, in accordance with the needs of modern armies, will probably become more pronounced in the future. It began with the provision of demolition equipment for the cavalry pioneers.
