Arabian Arches, their shapes are of three sorts, the horseshoe, the semicircular, and the pointed. Often they are enriched by a sort of feathering or foliation around the arch, and this ornament is closely akin to Gothic work, which it preceded by a considerable time. The Arabian style, known also as Saracenic and Moorish, is a fanciful composition in which details from Egypt and Greece and Rome are alembicated with “the light fantastic lattice-work of the Persians.” To-day we find its graceful influence in the greatest bridges at Isfahan, [213], and also in much Spanish work, [28-9], [285-6], [288]. Some writers believe that pointed arches were invented by the Arabs, yet they were built in Egypt during the Fourth Dynasty, [155-6], and also by the Babylonians, [275 footnote]. The Saracenic pointed arch was a forerunner of the Gothic pointed style, and it became familiar to the Crusaders, [86-93]; but we must draw a wide distinction between the pointed arch and the pointed Gothic style. Arabian architects did not achieve an upward flight and rhythm akin to the vertical principle of inspired Gothic; their buildings preserved the horizontal line which gave and gives character to classical traditions, [152], [153], [336]. If, then, the pointed arch in Europe was borrowed from Arabian architects, as many antiquaries believe, [88], it passed through a great transformation in technical sentiment, and became an original inspiration.

Boats ought to be added to the remarks on [page 58], or to the first section of the second chapter ([pp. 109-12]), for primitive man got his first boats from Nature. The earliest were floating branches and trees on which men sat astride, drifting with the current of rivers; the later were trees hollowed out by decay, which became models for dug-outs. “Between the primitive dug-out and a modern man-of-war there is, apparently, an impassable gulf; but yet the two are connected by an unbroken chain of successive improvements all registering greater efficiency in mechanical skill. Each of those intermediate increments constitutes a numbered milestone in the history and development of navigation.”—Dr. Robert Munro.

Boats, Bridge of, at Cologne, [1]. It will be remembered that Julius Cæsar frequently made use of boat-bridges, and that Xerxes, four hundred and eighty years before the Birth of Christ, made a bridge of boats across the narrowest part of the Hellespont, between the ancient cities of Sestus and Abydus. So the boat-bridge at Cologne, like the wooden pontoon, has an old and fascinating lineage, yet a modern bridge was going to displace it when the present Great War began. “Kultur” cancels history.

Brackets, below the parapet of the Pont Neuf at Paris, [321]. Brackets are ornamental projections from the face of a wall, to support statues and other objects. Some are adorned only with mouldings, while many are carved into angels, or foliage, or heads, or animals. Parker says: “It is not always easy to distinguish a bracket from a corbel; in some cases, indeed, one name is as correct as the other.” See Brangwyn’s drawing of the Pont Neuf facing [page 320].

Bradford-on-Avon, Wiltshire, the bridge there has a tiny oratory, [231-2], which was profaned after the Reformation, becoming a “lock-up,” and then a powder magazine, [232]. The bridge has nine arches; the two pointed ones uniting the oratory to the bankside have ribbed vaults, and the others are round-headed arches with double rings of voussoirs, [305 footnote]. Originally the bridge was a narrow one for packhorses, but it was widened in 1645, or thereabouts. A hospital used to stand at one end of the bridge, and doles of charity for it may have been collected in the little place of prayer. Leland admired this bridge, and noted its nine fair arches of stone, and a fair large parish church standing beneath the bridge on Avon ripe.

Bridge built with Arches, its anatomy. Professor Fleeming Jenkin says: “An arch may be of stone, brick, wood, or metal. The oldest arches are of stone or brick. They differ from metal and from wooden arches, inasmuch as the compressed arc of materials called the ring is built of a number of separate pieces having little or no cohesion. Each separate stone used in building the ring has received the name of voussoir, or archstone. The lower surface of the ring is called the soffit of the arch. The joints, or bed-joints, are the surfaces separating the voussoirs, and are normal to the soffit. A brick arch is usually built in numerous rings, so that it cannot be conceived as built of voussoirs with plane joints passing straight through the ring. The bed-joints of a brick arch may be considered as stepped and interlocked. This interlocking will affect the stability of the arch only in those cases where one voussoir tends to slip along its neighbour. The ring springs from a course of stones in the abutments, called quoins. The plane of demarcation between the ring and the abutment is called the springing of the arch. The crown of an arch is the summit of the ring. The voussoirs at the crown are called keystones. The haunches of an arch are the parts midway between the springing and the crown. The upper surface of the ring is sometimes improperly called the extrados, and the lower surface is more properly called the intrados. These terms, when properly employed, have reference to a mathematical theory of the arch little used by engineers. The walls which rest upon the ring along the arch, and rise either to the parapet or to the roadway, are called spandrils. There are necessarily two outer spandrils forming the faces of a bridge; there may be one or more inner spandrils. The backing of an arch is the masonry above the haunches of the ring; it is carried back between the spandrils to the pier or to the abutment. If the backing is not carried up to the roadway, as is seldom the case, the rough material employed between the backing and the roadway is called the filling. The parapet rests on the outer spandrils.”