NIAGARA LIMESTONE. 341 



given, and, more especially, from the local details that follow, it will 

 appear that these several portions occur in such a way as to require 

 some discrimination, if the best quality of rock is to be. chosen; and 

 it is hoped this report will furnish some assistance in making a snit- 

 lable selection. 



I Kilns for the reduction of lime have been established along its en- 

 tire length. These vary in construction, from mere rude domes of 

 bowlders to approved patent kilns. And yet some of each class were 

 found abandoned, while others were doing a profitable bxisiness. It 

 was observed that, in many cases, an impure rock had been burned. 

 In some instances, this was pardonable, as no better was exposed in 

 the vicinity, and the local demand warranted the use of such as was 

 accessible, until improved means of communication supplied a supe- 

 rior article from other sources; but in other instances, it is evident 

 that the failure was due to the use of inferior rock, when a superior 

 ore existed in the immediate vicinity. 



Properly selected, a very excellent lime may be made from this 

 formation. A considerable quantity of stone may be selected, in 

 which the impurities are less than one jper cent, of the whole; much 

 additional may be found, in which they are less than two per cent., 

 and an inexhaustible quantity, in which they do not exceed three per 

 cent. The large percentage of magnesia is an advantage, for it is a 

 well established fact that dolomite makes a stronger cement than 

 simple limestone. At many localities, the better class of rock is 

 used, and an excellent product obtained. Practical suggestions in re- 

 lation to selection will be found in Vol. I, where they are given i/o 

 save constant repetition. Numerous statistics relating to the in- 

 dustry were taken ; but they could not be made suiSciently complete, 

 accurate, and uniform to justify publication here. 



At some localities, it is claimed that the lower beds of this forma- 

 tion are suited to the manufacture of hydraulic lime, and analyses I 

 and II, given above, were made to ascertain upon what basis this 

 claim was founded. The composition, it will be seen, is quite difl'er- 

 from that of the celebrated hydraulic cements, and would not justify 

 an expectation that this rock would produce an hydraulic lime that 

 would have more than a local market. It will doubtless furnish a 

 serviceable substitute for the more expensive cements, for certain 

 purposes, where common fat lime will not answer. 



Kock obtained from Clifton is used at Appleton as a flux for Lake 

 Superior iron ores, and is said to work satisfactorily. The rock is 

 obtained from the fallen masses on the slope below the cliff, which 

 consist of a mingling of the several strata. The analysis above given 



