36 LOWER PENINSULA. 



evaporation. It escapes by subterranean crevices, which become 

 visible after the water has run off. The steep embankments of 

 the northeast end of the lake are formed by the brecciated lime- 

 stones of the water-lime group, which are quarried there and burned 

 into lime. 



Little Lake, in the town of Bedford, Section 15, is another sink- 

 hole of large dimensions. It sometimes becomes perfectly dry, 

 which never happens with Ottawa Lake. The rock crevices through 

 which the water disappears were quite conspicuous in the emptied 

 lake bottom at the time of my visit. Four miles north of Ottawa 

 Lake, on the land of Mr. Cummins, in the town of Whiteford, be- 

 tween Sections i and 2, another large sink-hole is observable, which 

 during the summer and fall-time is perfectly dry and partly over- 

 grown with grass. The centre of this depression is about 18 feet be- 

 low the level of the surrounding country ; a part of its bottom is 

 formed of naked rock ledges fissured by deep, vertical crevices. The 

 owner of the place informs me that during the spring this depres- 

 sion is filled with water which contains large fish, although I saw 

 not a drop of water in it at the time of my visit. When the water 

 begins to sink, it escapes quickly, and at the spot where the crev- 

 ices are, a whirlpool draws them in with a distinctly audible, 

 rushing noise. The larger fish being unable to get off with the 

 water, are left on the dry bottom to die. From the fact of the 

 appearance in these periodical water-basins of full-grown fish of the 

 kind usually found in Lake Erie, it has become the general belief 

 of the inhabitants that a direct connection exists between these 

 sink-holes and that lake, which suggestion has in it much of prob- 

 ability. All limestone formations are apt to be undermined and 

 eaten out by the water flowing through their crevices, which is 

 more or less charged with carbonic acid, and thus rendered a power- 

 ful solvent for the limestone. The old sandy beach-lines encircling 

 this district bear clear testimony to the fact that all this part of 

 the country was at a period not very remote a part of the bottom 

 of Lake Erie, whose waters leached out the softer, more soluble 

 ledges of the lime rock, and left the harder layers as roofs over the 

 eroded cavities. After the receding of the water from this ground, 

 leaving behind a deep, muddy sediment, which forms the present 

 rich soil, the roofs of these subterranean cavities broke down, 

 in some cases forming sink-holes that remain in connection with 



