476 



REPORT OF NATIONAL MUSEUM, 1899. 



above. W. Ferguson gives 1 the following analyses of molding sand 

 in actual use in his foundries: 



Sands containing lime or alkalies, that is those containing free calcite 

 or feldspathic granules, are sometimes liable to fusion in the case of 

 heavy castings. It is customary in such cases to coat the surface of 

 the mold with graphite. 



Sands suitable for ordinary castings are widespread, though the 

 finer grades are often brought considerable distances, some of those 

 used in bronze casting in America being imported from Europe. In 

 the United States the beds are alluvial deposits of slight thickness. 

 Large areas occur in New York State, in counties extending from the 

 Adirondacks to New Jersey. At date of writing a very considerable 

 proportion of the material used in the eastern United States is dug in 

 Selkirk, Albany County, New York. (Specimen No. 61044, U.S.N.M.) 



Nason states that these sands occur in beds varying from 6 inches to 

 3 feet or even 5 feet in thickness. They immediately underlie the 

 surface soil and overlie coarser, well stratified sand beds more nearly 

 allied to quicksands. 



In gathering the sands for market, a section of land 1 or 2 rods in 

 width is stripped of its overlying soil down to the sand, which is then 

 dug up and carried away. When the area thus exposed is exhausted, 

 a like area, immediately adjoining is stripped, the soil from the second 

 being dumped into the first excavation. By this method the field, 

 when finally stripped of its molding sand, is ready again for cultivation. 



It is estimated that a bed of sand 6 inches in thickness will yield 

 1,000 tons an acre. The royalty paid the farmers from whose land it is 

 taken varies from 5 to 25 cents a ton. Some 60,000 to 80,000 tons are 

 shipped annually from Albany County alone. 



The Selkirk molding sand is of a yellow-brown color, showing under 

 the microscope angular and irregular rounded particles rarely more 



1 Iron Age, LX, December, 1897, p. 16. 



