The simplicity and monotony of ornamentation during this epoch is especially remarkable. Art was then confined to the mere representation of a certain number of lines and geometrical figures. They were similar to those represented in fig. 206, and were applied to all kinds of objects--weapons, vases, utensils and trinkets. None of them attempt any delineation of nature; this idea does not seem to have entered into the head of man during the bronze epoch. In this respect they were inferior to their predecessors, the inhabitants of the caves of Périgord, the contemporaries of the mammoth and the reindeer. [Illustration: Fig. 206.--Principal Designs for the ornamentation of Pottery during the Bronze Epoch.] During the period we are now considering, commercial intercourse had assumed an activity of a totally different character from that manifested during the Stone Age. It became necessary to procure tin, which was indispensable for the manufacture of bronze. As no tin ore could be found in Switzerland, the inhabitants, doubtless, went to Saxony in order to obtain it. The traffic must have been carried out by means of barter, as is customary among all infant nations. Flint, which likewise did not exist in Switzerland, was necessarily procured from the surrounding countries which were more fortunate in this respect. No country was more favoured on this point than France; commerce must, therefore, have existed between the two countries. At Concise, in Switzerland, some pieces of white coral were found, and at Meilen, on the banks of the Lake of Zurich, some fragments of amber; from this we may conclude that during the bronze epoch the inhabitants of Switzerland traded with the inhabitants of the shores of the Mediterranean and the Baltic. Among the other specimens of foreign productions, we must not omit to mention graphite, which was used to surface pottery, amber beads, and even a few glass trinkets suitable for female adornment. We will now pass on to the system of food adopted by man during the bronze epoch. Researches made in various lacustrine settlements have furnished us with very circumstantial information upon the system of food customary among the earliest inhabitants of Switzerland. From them we learn that these men did not live solely upon the products of fishing and hunting, but that they possessed certain ideas of agriculture, and also devoted themselves to the breeding of cattle. We shall enter into a few details as to this eminently interesting aspect of their history, taking as our guides Professors Heer and Rütimeyer, the first of whom has carefully examined the vegetable remains, and the second the animal relics which have been found in the lacustrine settlements of Switzerland.