STATISTICS OF THE AMERICAN INDUSTRY. 289 



ble quantities. Even now few are aware of the great extent of the rock 

 and still fewer understand how to trace out the situation of favorably 

 located new quarries. 7 ' 



During the six years that had elapsed since 1837, however, the in- 

 dustry seems to have grown rapidly, for in his final report (1843) Mather 

 states that sixteen firms, working sixty kilns, were then operating in 

 the Rosendale district. He estimated the product at 500,000 to 600,000 

 barrels per year, and notes that about 700 men were employed in the 

 quarries, in the mills, and in handling the cement. 



After the industry had become established in New York, it was taken 

 up soon in several other States. It is a noteworthy fact, first pointed 

 out by Mr. Lesley, that all these early plants were located along canals, 

 and that in each case the natural-cement rock was discovered through 

 search for a satisfactory mortar material for canal masonry. 



Statistics of the American Industry. 



Since within very wide limits of composition any clayey limestone 

 will give a natural cement on burning, it can readily be seen that sat- 

 isfactory natural-cement materials must be widely distributed and 

 of common occurrence. Hardly a State is entirely without limestones 

 sufficiently clayey to be available for natural-cement manufacture. 

 The sudden rise of the American Portland-cement industry, however, 

 has acted to prevent any great recent expansion of the natural-cement 

 industry. It would be difficult to place a new natural cement on the 

 market in the face of competition from both Portland cement and from 

 the older and wen 1 -established brands of natural cement. Such new 

 natural-cement plants as have been started within recent years have 

 mostly been located in old natural-cement districts, where the accu- 

 mulated reputation of the district would help to introduce the new 

 brand. The only exceptions to this rule, indeed, were the Pembina 

 plant in North Dakota, the Rossville plant in Georgia, and a plant in 

 the State of Washington. Of these the Pembina plant was established 

 with the intention of making Portland cement, but the raw materials 

 soon proved to be unsuitable, and the plant was converted. The plant 

 in Washington is located in an area where any kind of cement is readily 

 salable. The Rossville plant was built by an Akron, N. Y., cement 

 manufacturer, to utilize a peculiarly satisfactory natural-cement rock. 



The following table taken from the annual volume on Mineral 

 Resources, issued by the U. S. Geological Survey, shows the quantity 

 and value of the natural cement produced in the United States in 1901, 

 1902, and 1903: 



