EXCAVATING THE RAW MATERIALS. 



373 



Steam-shovels are in use at the plant of the Purington Paving Brick 

 Company, at Galesburg, 111. Here a bank of firm shale is drilled, shaken 

 with black powder, and then handled entirely by steam-shovel. The 

 following detailed figures of cost have been recently published by Mr. 

 C. W. Purington. 



The figures cover the handling of 17,422 cubic yards of shale in 

 one month of twenty-six nine-hour days. This shale was dug from a 

 50-foot bank with a Model 90 Barnhart shovel with 2-yard dipper. 

 It was delivered to twenty 2-yard cars and trammed in two directions 

 (1500 and 2000 feet respectively) to the bottoms of two inclines. It was 

 then hoisted by cable to hoppers placed at an elevation of 20 feet above 

 the track and dumped into the hoppers. 



TABLE 167. 

 DETAILED COSTS OF STEAM-SHOVEL WORK. 



(PURINGTON.) 



These figures do not include charges for superintendence, oil, waste, 

 etc. If these be included, the cost of the steam-shovel work will be 

 about 5 cents per cubic yard. If the cost of drilling and blasting be 

 added, the total cost of handling the shale from the bank to the hop- 

 pers may be about 6 cents per cubic yard. Of this the blasting, dig- 

 ging, etc., amounts to about 4 cents per yard, while the tramming, hoist- 

 ing, and dumping will amount to the remaining 2 cents. 



In handling shales, steam-shovels are usually very effective exca- 

 vators, for here the material is physically homogeneous and requires 

 only one light blasting to break it into fragments that can be readily 

 handled by the shovel. This is well brought out by the itemized costs 

 given above for the Galesburg shale quarry. 



