144 ELEMENTARY FORESTRY. 
own estimators. The number of trees on typical areas, as an 
acre in each forty, may be counted, and the sizes estimated. 
Often all timber trees on a forty-acre lot are counted, and the 
number of logs per 1,000 feet board measure estimated. 
For an inexperienced person a good method would be to 
caliper all trees on typical areas of the tract, and then compute 
the stand from the cross-sectional area and the average length of 
timber stick, which could be estimated very closely after a little 
practice. The greatest dificulty in this work lies in the selection 
of typical areas and sample trees. All forestry measurements 
and estimates are only approximations, and it is often found 
necessary to modify working plans to meet new information 
and changed conditions. 
MEASUREMENT OF LOGS AND LUMBER. 
Logs are Measured in Feet Board Measure by taking 
the length and diameter at the small end, and by reference to a 
table the corresponding number of feet board measure is found. 
This is not usually accurate, but seems to be sufficiently so to 
satisfy both buyer and seller in this state. Lumber is measured 
in square feet of surface of a board one inch in thickness, com- 
monly called board measure, or B. M., for short. 
Scaling Logs in Minnesota is a Simple Matter. It is 
done after they are cut from the tree and marked, wherever con- 
venient,—in the woods, on skidways, on cars, on the river, or 
elsewhere. For straight, sound logs no experience is necessary, 
but for defective logs the scaler’s judgment is depended upon to 
make proper deduction, so as to get out good lumber. Private 
scalers may be employed by those interested, but, to avoid possi- 
ble litigation over sales, it is advisable to have the surveyor gen- 
eral of logs and lumber for the district appoint an official scaler 
to do the work. The scalers enter in a book carried for the pur- 
pose the number of logs scaled, the length, the feet B. M., the 
mumber of each log if numbered, the section, township and range 
where cut, and the markings. These books are kept on file in 
the surveyor general's office for future reference. There are 
seven lumber districts provided for by law in Minnesota, but in 
only five has it been found necessary to open ofhces, namely, at 
Stillwater, Minneapolis, Wabasha, Duluth and Crookston. 
