70 AN EXPERIMENT WITH A STEAM DRIEI. 



COMPARATIVE COST OF MOVING ROAD MATERIAL 



Different materials moved were as follows: Rock thrown 

 out by blasting, rock from an old wall, clay from barn cellar, 

 hard-pan full of bowlders and small stones, a small amount of 

 cinders and gravel easily handled. For details of number of 

 yards, length of haul, cost, etc., see table, page 62. 



The cost of moving ledge rock is altogether too great to 

 allow its profitable use in ordinary embankment. When, 

 however, the rock must be moved, it can often be used to 

 advantage in grading. Deep drilled holes, a good quantity of 

 at least 75 per cent, dynamite, and a battery for use in explod- 

 ing were found necessary for the satisfactory breaking up of 

 masses of rock, while a hand derrick, which may be hired for 

 about one dollar per day, was found to give far more economi- 

 cal results in handling rock than could be attained without. 

 Without going into details, all these points are of special 

 importance and can hardly be emphasized too strongly when 

 rock-work is under consideration. 



We see by examination of table that the economic value 

 of an old wall for grade at a distance above fifty feet is exceed- 

 ingly problematic. The size of the stone will be the determin- 

 ing factor. In the case under consideration, about two thirds 

 of the stone had to be handled with bars and many stones were 

 loaded upon the drag by aid of horses. When we consider 

 further the additional expense required in packing the rocks 

 together to make a fairly compact fill, it may be regarded as 

 settled that it would be cheaper to draw earth at least one half 

 mile than to utilize a wall of large stone over fifty feet distant. 



The cost of handling earth varied from 15 to 66 cents per 

 yard, the variation being largely due to the difference in the 

 efficiency of the shovelers and not appreciably to differences in 

 length of haul as great as one fourth mile. The highest cost, 

 except for gravel, viz., 40 cents, was for earth moved only a 

 little more than one fourth mile. Again, it can not be too 

 strongly emphasized that the selection of the right number of 

 shovelers and the right number of teams, proportioned to the 

 distance to be covered and the kind of material to be moved, is 

 a vital factor. I have in mind one third section of a town 



