﻿86 



INDIAlvTA UNIVEESITY 



Another by-product which is likely to appear in the near fu- 

 ture is stone brick, made from the crushed waste. Of recent 

 years sand brick and cement brick have taken their places among 

 the building materials, and experiments are now being made 

 with the manufacture of stone brick from the waste from the 

 mills in New York City. The success of these experiments now 

 seems well-nigh assured, and if they do prove successful, the in- 

 troduction of the manufacture of stone brick will be only a ques^ 

 tion of time. 



The oolitic limestone industry presents certain profit-deter- 

 mining features peculiar to itself. The depth of stripping has 

 in many cases increased the cost of production so greatly as to 

 result in the abandonment of the particular quarry opening. 

 This is especially likely to occur where the opening is along the 

 side of a rather steep hill, for, as the almost horizontal strata are 

 worked backward into the hill, the stripping becomes deeper and 

 deeper. Those quarries opening on the top of the hill are less 

 likely to incur this difficulty. 



There is compensation for this loss, however, in the fact that 

 within certain limits the amount of waste in the quarry is in 

 inverse proportion to the depth of the stripping-^ ; for the 

 heavier the stripping the less likely is the disintegration of the 

 good stone due to the percolation of surface waters carrying with 

 them more or less acid. Besides the disintegration of the upper 

 portion of the bed, waste may result from ''mixed" stone, from 

 coarseness of texture, from the vertical joint seams, and from 

 the stylolites or suture joints— 'crow- feet " or "toe-nails," the 

 quarrymen call them. Ordinary lamination planes are very rare 

 in the interior of the bed, but these extraordinary bedding 

 planes, though nearly horizontal, probably cause more waste than 

 any other structural feature of the stone. 



Many other causes contribute to a considerable variation in 

 the rate of profits. Personal relations between employers and 

 workmen occasionally operate to hold wages at a lower level and 

 thus increase profits. Location near the homes of the workmen 

 may give a particular quarry an advantage in labor cost over an- 

 other, whose employees must use the railway in going to and 

 from their work. In some cases such an adavantage may be par- 

 tially offset by increased taxation, but not altogether so. It 

 seems, however, that many workmen prefer to live in town rather 



-'oind. Geol. Report, xxi, 326. 

 21 Ind. Geol. Report, xxi, 305. 



