FORESTRY QUARTERLY 



Vol. XIV March, 1916 No. 1 



AN EFFICIENT SYSTEM FOR COxMPUTING TIMBER 



ESTIMATES 



By C. E. Dunston' and C. R. Garvey- 



With the use of an adding machine and a simple device for 

 holding timber estimate sheets and volume tables, it has been 

 possible for two men to compute the estimates on about 4,000 

 sheets in approximately thirty days, a task which, without these 

 aids, would have taken the same men not less than eighty days 

 to complete. The field work of the timber estimate in question 

 wa^ carried on in the field season of 1915, and covered approxi- 

 mately 80,000 acres of the Quinaielt Indian Reservation. This 

 Reservation, with an area of about 250,000 acres, is located just 

 north of Grays Harbor on the Pacific Coast, in a region of heavy 

 stands of Western hemlock. Western Red cedar, Sitka spruce, 

 Douglas fir, Amabilis fir and a small percent of Western White pine. 

 The valuation strip survey method of estimating was employed, 

 merchantable trees being tallied by diameter at breast height 

 and number of thirty-two-foot logs. Since merchantable trees 

 range in size from 14 to over 100 inches d. b. h. and from one to five 

 thirty-two-foot logs, and since the major part of the cruised area 

 contains a stand in excess of 50,000 feet b. m. per acre, it will be 

 seen that the work of computing these estimates without the 

 mechanical aid afforded by the adding machine and the case, 

 herein described, for holding estimate sheets and volume tables, 

 would have been a long and laborious undertaking. 



A diagram of this case with a sample estimate sheet and spruce 

 volume table in place appears in frontispiece. It consists of a thin 

 board with narrow wooden strips A and B at top and side edges 

 and a similar strip D which forms a partition between compart- 

 ments for estimate sheets and volume tables respectively. The 

 dimensions of this case may be varied to suit special requirements 



^ Supervisor, U. S. Indian Service. 

 * Forest Assistant. 



^c 



