These indications of pile-dwellings, though strengthened by further observations by M. Vallier in the following year, really contributed little to the elucidation of the problem as to the period to which they belonged; so that the work of M. Vallier, "La Légende de la Ville d'Ars sur les Bords du Lac de Paladru," leaves the question much in the same position as it was left by Professor Fournet, who had already suggested, in 1860,[48] that the legend of the buried city had its origin in the former existence of lake-dwellings. It remained to M. Ernest Chantre, of Lyons, to make the first practical investigations to clear up the mystery. To this line of research he was led by the encouragement and knowledge he had received at the first meeting of the International Congress of Prehistoric Archæology, held at Neuchâtel, in 1866, when he had an opportunity of being initiated by Professor Desor and others in lacustrine research. His first efforts, an account of which was published in the _Matériaux_ for 1867, showed that two of the stations mentioned by M. Vallier belonged to the Iron Age. Learning then that engineering works were in progress for regulating the outflow of the waters of this lake, which would have the effect of lowering its level, M. Chantre deferred his proposed excavations till these more favourable conditions should be accomplished. His subsequent investigations, conducted in the autumn of 1870, were confined to the first-named station (Grands Roseaux), which, from his former experience, gave greater promise of archæological results. From it he had already picked up some bones of the ox, pig, stag, etc., the kernels of a species of small cherry and of two kinds of plums, fragments of pottery of a different kind from any found in the Swiss lake-dwellings, an iron knife, and a wooden comb. Owing to the lowering of the lake the station was now (1870) a foot above water, and it could be easily examined by the spade on _terra firma_. In the excavations which ensued the following strata were met with:--(1) Eight inches of peaty mud and roots of water plants; (2) About eighteen inches of peat containing bits of worked wood and bones; (3) Ten inches of peat containing bones, fragments of pottery, and a great variety of antiquities; (4) Underneath this peat was the whitish lake sediment known as shell-marl.