234 geology or OHIO. 



the same part of the county which, without penetrating the rock, have 

 similar mineral water. They, however, derive it from the gravelly sheet 

 which lies on the rock, the water of which must be considerably affected 

 by streams from the rock. Such springs and wells as depend on the 

 gravel or sand within the hard-pan could not be influenced by the 

 underlying rock. Hence they are not known to show only those mineral 

 characters that they can obtain in the Drift. They are sometimes cha- 

 lybeate, but usually show no impurities whatever. 



The well of Mr. George Momany seems to be influenced by the 

 fluctuations of the level of Lake Erie. A westerly wind for a few days 

 depresses the west end of the Lake, and the rise of water in the well is 

 less. When a wind from the east or north-east prevails, it overflows at 

 greater height. This was noticed by Mr. Momany by reason of the well 

 ceasing to flow at certain times, owing to the outflow being within an 

 inch of the greatest rise. It seems, therefore, that the height to which 

 water will rise in artesian wells depends not altogether on the level of 

 their supply, but also on the facility of escape below. This point is 

 supposed to be about seven feet above Lake Erie, and the actual' set- 

 back of dead-water from that obstruction could not be much above the 

 level of that lake. This seems to be an illustration of that principle 

 of hydrostatics, but little known, that an obstruction in a current, as 

 in a river, not only causes a certain amount of "dead-water" near it, 

 but also retards, by a kind of reaction, the water higher up the stream, 

 when the rapidity of the current is not perceptibly changed to the eye. 



MATERIAL RESOURCES. 



Besides the deep and fertile soil that every where covers the county, 

 and furnishes the chief means of material wealth, Ottawa county is 

 generously supplied with other natural resources, the immediate pro- 

 duct of the underlying rock. The quarries in the Lower Corniferous 

 limestone in the eastern part of the county, known as the " Marblehead 

 Quarries," are highly prized for the fine blocks of a variegated stone, 

 suitable for the largest structures, which they produce, and which are 

 extensively used not only in many places in the State of Ohio, but in 

 neighboring States. They will be more fully noticed in the report on 

 that part of the county. 



The shipments of gypsum from the Plaster Bed quarries of George A. 

 Marsh, in the township of Portage, amount to six or eight thousand tons 

 per annum, bringing three dollars per ton. The gypsum is of unusual 

 purity and whiteness, with occasional delicate cloudings. The principal 

 ^markets for agricultural purposes are in Ohio, Kentucky, Indiana, and 



