412 



AMERICAN FORESTRY 



FIG. 2. 



In the accompanying illustration (Fig. 2) which shows a mine timbered 

 in the old way ; it can be seen at a glance how wasteful is the giving way of one 

 of the timbers and rendering all the rest useless. Also from the illustrations 

 (Plates I, II, III, and IV) of the concrete and steel construction, it will be 

 seen how much more efficient it is, for it obstructs the mine less and gives 

 much better support to the roof. Because of the amount of timber used in the 

 mines it has become necessary for mining companies to be also timber com- 

 panies. They found that they could the better inspect their timber when 

 it was their own and by cutting down profits in timber effect a great saving. 

 But even now timber is often accepted at the mine in such a condition that it 

 is doubtful whether its service in the mine would pay for the cost of setting 

 it, exclusive of the cost of the timber. A grave indictment is the loss of 

 life occasioned by bad setting, the criminal haste when the contract for setting 

 timbers in the mines is given to the company which is concerned only with 

 I>lacing the greatest amount of timber in the shortest possible time regardless 

 of where or how placed. Perhaps the ordinary mine owner is more concerned 

 with the loss of property than with the loss of his men, and often when mine 

 timbers have been so placed that they cannot properly resist the strain, the 

 whole outlay has been either a partial or a total loss. 



It has been argued against concrete and steel construction that it would 

 not be in line with reguhir practice of preparing a mine for, according to the 

 old way, timber was hauled into the mine, cut on the spot, and fitted in. With 

 concrete and steel construction measurements must be taken and the mine 

 must in a sense be made to fit the supports. But there is no doubt, and it has 

 never been argued, but that the modern construction is better able to stand 

 the strain, that it is safer to life and property and although the initial outlay 

 for concrete and steel is great, yet in the end a saving is effected. No figures 

 are yet obtainable as to the comparative cost. 



Much has been done by trained foresters to try to prolong the life of 

 mine timbers. They have made studies of the subject and their conclusions 

 have had weight with mine owners. In lOOB, the Forest Service, in cooperation 

 with the Philadelphia & Reading Coal and Iron Company, planned and carried 

 on a series of exjeriments to determine the best methods of prolonging the 

 life of mine timber. The results of that study are contained in a bulletin 



