12 



BULLETIN 77, U. S. DEPARTMENT OF AGRICULTURE. 



ber used in the mines, and information concerning the life of the 

 timber and the extent to which methods to prevent decay had been 

 employed. A small part of the material included may have been used 

 in structures above ground. 



Reports were requested from 823 operators, 110 of whom were 

 coal-mine and 713 metal-mine operators. Out of 352 replies, 179 

 (15 coal-mine and 164 metal-mine operators) reported that no timber 

 was used during 1911, while 173 operators reported the use of timber 

 on which the following statistics are based. 



In addition to the material reported by the tables, about 1,745 

 cords (or 872,500 b. m.) were used for fuel. 



Nearly all the timber used came from within the State. About 

 800,000 board feet was reported as coming from outside, mostly 

 Douglas fir from Oregon, with a small amount of pine from New 

 Mexico. 



The timbers for use in the coal mines ranged in size from about 5 

 to 7 inches in diameter and from 7 to 18 feet in length. In the 

 metal mines 8 to 10 inch diameters were the principal sizes, though 

 timbers varying from 6 to 20 inches were reported. Lagging was 

 usually 3 to 4 inches at the small end, and mine ties were 4 by 4 or 

 4 by 5 inches in section and from 36 inches in length in the metal 

 mines to 54 inches in the coal mines. 



Table 5. — Amounts and values of mine timbers used in Colorado in 1905, based on 



reports of mine operators. 





Num- 

 ber of 

 mines. 



Total amounts. 



Total values. 



Cost per M b. m. 



Mines reporting. 



Round, 

 M b. m. 



Sawed, 

 M b. m. 



Round. 



Sawed. 



Round. 



Sawed. 





69. 



418 



7,893 

 18, 152 



457 

 13, 061 



$153, 152 

 284, 861 



$15, 428 

 251,798 



$19.40 

 15.69 



$33. 76 





19.28 







Total (all mines) 



487 



26,045 



13.518 



438, 013 



267. 226 



16.82 



19.77 













39,5fi3Mb.m. 



$705-239 



















Table 6. — Amounts and values of mine timbers used in Colorado in 1911, based on 



reports of mine operators. 





Num- 

 ber of 

 mines. 



Total amounts. 



Total values. 



Cost per M b. m. 



Mines reporting. 



Round, 

 M b. m. 



Sawed, 

 M b. m. 



Round. 



Sawed. 



Round. 



Sawed. 





77 

 187 



10,859 

 6,601 



1,000 

 6,406 



$307, 372 

 139,030 



$20,368 

 141.185 



$28. 20 

 21.10 



$20.37 





22.00 









Total (all mines) 



264 



17,460 



7,406 



446,402 I 161,553 



25.50 



21.80 





24,$66 



$607,955 



















The amounts were reported in linear feet, in board feet (log scale), 

 in cubic feet, and in cords. To reduce these various units to the 



