FOREST INSTRUMENTS. 147 



In practice these discrepancies are equalized as the result of 

 the ordinary trade relations, and are not liable to work serious 

 injustice under present conditions, and are here stated only to 

 call attention to our crude methods of measuring timber. 



INSTRUMENTS USED IN FOREST MENSURATION. 



The Equipment of a Forester, while not extensive, must 

 be complete for the work in hand. He surveys the land, lays 

 out roads and ditches, cuts down trees and saws them into logs, 

 measures diameters of logs and growing trees, takes heights of 

 trees, determines rates of growth, estimates and measures tim- 

 ber and cordwood, and maps and plats his work. Where there 

 has been a survey of land by the government, as in this state, he 

 will not be called upon to make one, as maps sufficiently reliable 

 for his purpose may be had from official records; but to meet 

 all the requirements of his position the forester should be an 

 expert surveyor, and provided with all the necessary instruments 

 for the work, including drawing instruments, tables, stationery, 

 etc., for office work, in mapping and platting his field observa- 

 tions. The work of forestry mensuration is concerned mainly 

 with taking diameters and heights of trees, determining the areas 

 on which they stand and the rate of growth. 



For Measuring I,and Areas the ordinary steel tape, grad- 

 uated on one side in feet, tenths and hundredths, and on the 

 other side in links for convenience in computing acreage, is used 

 the loo-foot length being preferred. For the same purpose a 

 steel chain is also used, and with the chain or tape should be a 

 set of marking pins and ranging poles. In laying out small 

 rectangular areas, as a sample acre, a cross-staff head, an angle 

 mirror, or an angle prism is used; but for more extended sur- 

 veys and for road and ditch work a transit and level would be 

 advisable, while for the location of lost corners the magnetic 

 compass might have to be resorted to. 



For the Rough I,and Measurement of a Valuation 

 Survey a Steel Chain, Thirty-three Feet I/ong, is used. 

 This short chain is attached to a stout leather belt about the 

 waist of the tallyman, whose hands are then free to carry the 

 tallyboard holding 'notebook or tally blanks, and to work with a 

 lead pencil. A small magnetic compass by which the tallyman 

 directs his course is fixed on one corner of the tallyboard. 



