10 A MANUAL FOR NORTHERN WOODSMEN 



by opening of the joints. Chains have every tenth link 

 marked by a brass tag, and these tags have one, two, three, 

 etc., teeth, so that the number of links may be readily and 

 accurately counted. 



Chains change in length by use. The links may be bent 

 and the chain thus shortened, a matter which can readily 

 be adjusted by hammering; but more commonly a chain 

 increases in length from flattening of the links and wear 

 in the numerous joints. This may be corrected to a limited 

 extent by turning up the nuts which hold the handles. 

 Further effect may be had by taking out one or^more of the 

 rings which connect the links, or better still, by hammering 

 each link while it is held in a vise, and so distributing the 

 correction. 



The chain is so liable to change in length that provision, 

 should be made for testing it frequently. An unused tape, 

 known to be of true length, kept at home or only taken 

 off on long jobs, is the best and most convenient safe- 

 guard. 



2. THE TAPE 



Steel tapes are in wide use for general surveying, but 

 not usually among woodsmen because of their liability to 

 breakage. They have, however, distinct advantages. 

 They are light, so as to be leveled readily when measure- 

 ment is being made on a slope. They do not stretch. 

 There are no links to get kinked and so cause a false 

 measure. A tape for field use should be made of steel 

 ribbon from i to J inch wide and No. 30 to 32 thick. 

 Wider and thinner tapes are a nuisance in woods 

 conditions. 



Tapes are made of any length and graduated to suit the 

 work for which they are designed. One 66 or 33 feet long, 

 graduated to links, will best suit the needs of the timber 

 land surveyor. 



Some precaution must be taken with steel tapes. When 

 in use, they should be kept out at full length and never be 

 doubled on themselves, for, if doubled, they are easily 

 kinked and broken. When done up, they should be wiped 

 clean and dry, and so cared for as to prevent rusting. A 



