968 NEW YORK STATE MUSEUM 



crushed stone is used for road metal, concrete, railroad ballast, 

 etc. A test of the trap from Rockland Lake made in the laboratory 

 for road material at Washington D. C. gave the following re- 

 sults: Coefficient of wear, 13.2; per cent of wear, 3; weight 

 in pounds a cubic foot, 192.5; pounds of water absorbed a cubic 

 foot, .3; cementing value, 80. 



The production of trap rock in New York last year was valued 

 at $468,496. Of this total, $452,621 represented the value of 

 crushed stone, and $15,875 the value of paving blocks and building 

 stone. The total quantity of crushed stone made was 610,285 

 cubic yards, of which 280,516 cubic yards was reported as sold 

 for road metal, while the remainder was unclassified. The paving 

 blocks were quarried on Staten Island. 



TALC 



No important developments in the talc industry of St Lawrence 

 county were recorded during 1904. The mines and mills have been 

 working at a normal rate, in accordance with the market demand 

 for the product, which was of average character as compared 

 with previous years. With existing facilities the output could 

 be increased to much larger than present proportions so that there 

 is little incentive to start new enterprises in this field. 



The market for fibrous talc is limited almost entirely to the re- 

 quirements of paper manufacturing, and since it scarcely seems 

 probable that the other uses can be augmented to any great ex- 

 tent, the demand, doubtless, will continue to be governed b}^ the 

 conditions prevailing in that industry. So far as the American 

 paper trade is concerned, St Lawrence talc has become a staple 

 article, but there is still some room for extending the foreign 

 consumption, particularly in Great Britain where manufacturers 

 have been slow to recognize its advantages over other fillers. 

 Germany is the best of foreign markets and large quantities of the 

 product are exported annually to that country. That it can 

 compete successfully with the high grade German clays sold at 

 lower prices lends encouragement to the view that the exports 

 may be further increased. 



The superior qualities of talc from this region are primarily 

 due to its fibrous, pliable character. Thus in paper making it 

 not only serves as a filler, but the fibers felt together and strengthen 

 the paper stock. A much larger proportion of fibrous talc can be 

 incorporated in the pulp than is possible with clay or other ma- 

 terials composed of scaly or rounded particles. Among the chief 



