A book of bridges

by Walter Shaw Sparrow

With her incalculable partner, the irrational male, she and her family wander from district to district. At times they settle under a rock-shelter or in a cave, and make footpaths from it to watering-places and hunting-grounds. Here and there a river is crossed by stepping-stones, and more than one ravine is spanned by branches and by a fallen tree. What is their attitude to these things? The windfall tree-bridge, like every other gift from Nature, is a bane to them as well as a boon, for it is a road open to dangerous animals; as such it is a thing to be guarded, and many a fight in its defence occurs, creating traditions of bravery which are long remembered.

Further, as time goes on, and the progenitors of man become more human, the pressure of competitive life draws ever more and more attention to the incompleteness of natural bridges. For example, stepping-stones may be useless when they are needed most of all, in wet seasons and after storms; and the tree-bridge is so narrow that warriors cross it only one by one, so their slow attack gives a terrible advantage to a brave defence. These hindrances, so obvious and so unpleasant, make appeal to the inventive faculty that a few men possess. Not much is required. From four or five seedling ideas a great many improvements will grow; and now is the moment for us to choose a vague tentative date for the beginning of this gradual development.

Most people are bored by prehistoric archæology, because its earlier periods are as undated as is the oblivion of coma. So a date in obscure history, however tentative it may be, is very helpful; the mind rests on it, somehow, anyhow, and feels that the lost legions of the dead years left some oases in the Saharas of ancient time. And this point is not the only one that concerns the general reader who does generally read. In recent years the antiquity of handicraft has been extended very much by a “find” of eagle-beaked flint implements, with other tools, below the Pliocene deposits on the East Anglian Coast. The eagle-beaked flints are undoubtedly of human manufacture, and they carry back the ancient stone period of man to the Tertiary times. Sir Ray Lankester writes on this important subject, and his knowledge helps us a great deal, though we have to recover it from entangled sentences. For example[38]:—

“Evidence has been for twenty years or more in our possession (in the form of stone implements) of the existence of man in Europe in the warm period which preceded the Pleistocene, with its glacial clays and drifts and its gravels deposited on the sides of existing river valleys, sometimes 800 feet above the level of the bed to which the stream has now worn down its excavation, many miles wide. The discovery within the last four years of beautifully worked flint implements of the shape of an eagle’s beak (called ‘rostro-carinate’) and of other serviceable forms below the marine Pliocene shelly sands—known as the ‘Red Crag’ in Suffolk—separates the migrations and mixtures of human tribes and groups, of which we have any knowledge, by a huge chasm of geologic time from the date of the earliest European population. The best geologists have come to the conclusion that half a million years (and it may well be twice as many) separate us from the days before the Crag Sea laid down its shelly deposits on the East Anglian Coast. Yet there were skilful men—not mere ape-like creatures using sticks and roughly-broken stones, but men capable of making and admiring symmetrical, well-finished flint tools, and of using them to clean skins and to plane wood—living a human, creative, dominating life here in Western Europe in those immensely remote days. Probably enough, as great a period as separates those skilful men from us separated them from the earliest unskilful ‘commencing’ men of the tropical zone.”

GOTHIC BRIDGE AT VILLENEUVE-SUR-LOT, FRANCE

Yes, probably enough, but yet we must not suppose that handicraft in Western Europe has ever had a standard of uniform merit. As our own work is very often inferior both to that of the Romans and to that of the Middle Ages, so the eagle-beaked tools may denote nothing more than a local industry which a man of genius had originated. No other implements have been dug up from Pliocene deposits in other European localities, hence students of art and architecture cannot accept the generalisation advocated by Sir Ray Lankester. As well suppose that the whole of Western Europe produced in the same age many painters equal to the Van Eycks, or many bridge-builders of a piece with Caius Julius Lacer, or the good Saint Bénézet. It is enough to believe that at a date to be known vaguely as 500,000 B.C., a craftsman of genius lived and laboured in a district of Western Europe, now called the East Anglian Coast. How far his influence extended, or how long it lasted, we have no inkling yet; but it may have been the influence, not of a rare genius, but of a school tradition which migrating tribes had spread through many parts of Europe. Anyhow, the eagle-beaks are historic facts and their manipulative skill gives us the right to make reasonable inferences.

For example, we may infer that if the craftsman who made an eagle-beaked tool showed intelligence in some other useful ways, he did no more than common justice to his humanity. Suppose he cut down a tree with his flint axe, choosing one that grew aslant over a chasm or across a river; or suppose he piled stepping-stones together in the middle of a waterway, and then used this pier as a support for two tree-trunks whose far ends rested on the banksides. Neither of these ideas has more mother-wit than that which has enabled ants to bore tunnels under running water, and to make active bridges by clinging to each other in a suspension chain of their wee brave bodies. Not many human minds in any period of history have been as diligently rational as ants; but let us risk the conjecture that the first advance in bridge-making began among the rostro-carinate workmen probably more than half a million years ago.

To cut down a tree, in order to get a bridge at a chosen place, was a good idea in primitive enterprise, but it was not enough; it gave but little additional help in tribal wars, since it repeated the narrow footway, the main drawback of windfall tree-bridges. Two or three trees laid side by side were necessary, and at least two piles of stepping-stones to carry enough trees over a fairly wide river. Such were the first improvements that war and social life demanded from the wit of primitive mankind, and often they were demanded in vain for many long ages. Even at the present time there are tribesmen who feel well pleased with themselves when they make single and double tree-bridges. I am told, for instance, by Mr. T. Beddoes, a traveller and trader in Equatorial Africa, that often in his wanderings he has made and used a tree-bridge to cross a narrow creek, following a native method for the sake of its ready convenience. “The natives,” he writes, “cut down the tallest trees on a bank of the waterway that they intend to bridge, then they make a handrail with bush-rope fastened to short upright sticks which are placed about three feet apart. Bush-rope is made from creepers or from long cane vines. Sometimes an attempt is made to flatten the upper surface of the tree; but this work is uncommon, as African natives are lazy; they detest manual labour. There are trees that grow to an enormous height; one of them measured a hundred feet odd, so fairly wide creeks and streams can be bridged. But canoes are the favourite means of crossing rivers; they carry light loads well enough, and they need less labour than bridge-building.”