352 LECTURE XII. 



M. Troyon seems to have discovered the primitive Orsini 

 shells, clay-balls filled with pitch, which were thrown upon the 

 pile-works. Keller remarks on this point, " It is a pity that 

 when Troyon published his Habitations Lacustres, the many 

 lake stations in which Roman implements are found were 

 unknown ; he would, doubtless, have proved a third conquest 

 of the country, and a third burning of the pile-buildings, and 

 the decimation of the population as the concluding act of 

 the drama." 



On examining such stations as belong to the stone and 

 bronze period, it is found that the stone-period pile-work 

 forms, as it were, the nucleus around which the piles of the 

 bronze period extend and are progressive in depth. There 

 are, according to Desor, piles of the bronze period four to six 

 inches in diameter, thirty feet deep below the mean height of 

 the water level, which are driven in ten feet into the bed of 

 the lake. These piles supported platforms, as at Wauwyl, 

 above the water, and if we assume the height of these plat- 

 forms at four feet and the imbedding only at six feet, it yields 

 a total length of forty feet for a pile four inches in diameter, 

 which must have been driven in through a depth of thirty feet 

 water. This appears to me no slight task even for an engi- 

 neer of our own time, but for an architect of the bronze period 

 a manifest impossibility. We conclude hence, that at the 

 period of the erection of the stone piles the waters stood as 

 high as, or even a few feet higher, than at present, but that 

 they gradually retreated, which forced the pile builders to 

 follow the water. It is by this subsidence of the waters that 

 in the smaller lakes many pile-works were exposed, and then 

 abandoned, after which they were overgrown with peat, which 

 must have been rather dry as it contained in its lower strata 

 much wood. The waters rose again at a later period, the pile- 

 works were submerged in the water or buried under the gradu- 

 ally accumulating peat. The surface of the water must have 

 undergone various changes, so that the pile builders were 

 either obliged to follow the water or to settle on the land. 



Possibly the first stone-period buildings or stone hills, as they 

 might be called, were only artificial islands, like the so-called 



