72 THE WOODSMAN'S HANDBOOK. 



STRIP SURVEYS. 



The principle underlying the use of strip valuation surveys is 

 the measurement of trees on narrow strips distributed systematically 

 over the forest and covering, in the aggregate, a specified propor- 

 tion of the total area. In the practice of the Forest Service of the 

 United States Department of Agriculture the strip surveys are one 

 chain or 4 rods wide and 10 chains or 40 rods long, so that e^ch 

 covers just one acre, and thus the tree measurements and forest 

 descriptions of each acre may be kept distinct. 



A crew of at least three men is required to lay off the strips. 

 One, a tallyman, carries a notebook or tally sheets, and records 

 the species and their diameters as they are called out by two 

 calipermen; he also makes any necessary descriptive notes. The 

 strip is measured lengthways with a surveyor's chain — that is, 

 stretched on the ground. The tallyman carries the forward end 

 and one of the calipermen the other. The trees within an esti- 

 mated distance of 33 feet (one-half chain) on each side of the chain 

 are then calipered. Then the crew moves forward another chain 

 length and the process is repeated until 10 chains have been 

 measured. 



If there are four men in the crew one man lays the direction of the 

 strip with a compass and carries the forward end of the chain, two 

 men caliper the trees, and the fourth makes the records. The com- 

 passman directs the work of the crew, and sees that the calipering 

 is accurately done, that no unsound trees are measured, and that 

 the calipermen keep within 33 feet of each side of the chain; also 

 he make the observations for the descriptive notes, which he dic- 

 tates to the tallyman. As it is difficult for the compassman to direct 

 the course and at the same time make observations of the character 

 of the forest and oversee the work of the others, a fifth man Ls some- 

 times added to the crew. This enables the leader of the crew to 

 devote his whole attention to directing the work and making the 

 descriptive notes. 



If the trees are to be counted and not measured, two men in the 

 crew are sufficient, one to do the counting, the other to manage the 

 compass and the forward end of the chain, to record the counts, 

 and to take notes on the forest. 



