The winter of 1853-1854 was, in Switzerland, so dry and cold that the waters of the lakes fell far below their ordinary level. The inhabitants of Meilen, a place situated on the banks of the Lake of Zurich, took advantage of this circumstance, and gained from the lake a tract of ground, which they set to work to raise and surround with banks.

In carrying out these works they found in the mud at the bottom of the lake a number of piles, some thrown down and others still upright, fragments of rough pottery, bone and stone instruments, and various other relics similar to those found in the Danish peat-bogs.

This extraordinary accumulation of objects of all kinds on the dried bed of the lake appeared altogether inexplicable, and every one was at fault in their remarks; but Dr. Keller of Zurich, having examined the objects, at once came to a right understanding as to their signification. It was evident to him that they belonged to pre-historic times. By an association of ideas which no one had previously dreamt of, he perceived that a relation existed between the piles and the other relics discovered in the vicinity, and saw clearly that both dated back to the same epoch. He thus came to the conclusion, that the ancient inhabitants of the Lake of Zurich were in the habit of constructing dwellings over the water, and that the same custom must have existed as regards the other Swiss lakes.

This idea was developed by Dr. Keller in five very remarkable memoirs, which were published in German.[31]

This discovery was the spark which lighted up a torch destined to dissipate the darkness which hung over a long-protracted and little-known period of man's history.

Previous to the discovery made on the dried-up bed of the Lake of Zurich, various instruments and singular utensils had been obtained from the mud of some of the lakes of Switzerland, and piles had often been noticed standing up in the depth of the water; but no one had been able to investigate these vestiges of another age, or had had any idea of ascribing to them anything like the remote antiquity which has since been recognised as belonging to them. To Dr. Keller the honour is due of having interpreted these facts in their real bearing, at a time when every one else looked upon them as nothing but objects of curiosity. It is, therefore, only just to pronounce the physician of Zurich to have been the first originator of pre-historic archæological science in Switzerland.

In 1854, after the publication of Dr. Keller's first article, the Swiss lakes were explored with much energy, and it was not long before numerous traces of human settlements were discovered. At the present day more than 200 are known, and every year fresh ones are being found.[32]

Thanks to the activity which has been shown by a great number of observers, magnificent collections have been formed of these archæological treasures. The fishermen of the lakes have been acquainted, for many years back, with the sites of some of these settlements, in consequence of having, on many occasions, torn their nets on the piles sticking up in the mud. Numerous questions were asked them, and they were taken as guides to the different spots, and ere long a whole system of civilisation, heretofore unknown, emerged from the beds of the Swiss lakes.

Among the lakes which have furnished the largest quantity of relics of pre-historic ages, we may mention that of Neuchâtel, in which, in 1867, no less than forty-six settlements were counted; in Lake Constance (thirty-two settlements); in the Lake of Geneva (twenty-four settlements); in the Lake of Bienne, canton of Berne (twenty settlements); in the Lake of Morat, canton of Fribourg (eight settlements).

Next come several other lakes of less importance. The Lake of Zurich (three settlements); the Lake of Pfæffikon, canton of Zurich (four settlements); the Lake of Sempach, canton of Lucerne (four settlements); the Lake of Moosseedorf, canton of Berne (two settlements); the Lake of Inkwyl, near Soleure (one settlement); the Lake of Nussbaumen, canton of Thurgau (one settlement); the Lake of Zug, &c.