DETAILED INSTRUCTIONS

Part of Tree to be Tested

(a) For determining the value of tree and locality and the influence on the mechanical properties of distance from the pith, a 4-foot bolt will be cut from the top end of each 16-foot butt log.

(b) For investigating the variation of properties with the height of timber in the tree, all the logs from one average tree will be used.

(c) For investigating the effect of drying the wood, the bolt next below that provided for in (a) will be used in the case of one tree from each locality.

Marking and Grouping of Material

The marking will be standard except as noted.  Each log will be considered a “piece.”  The piece numbers will be plainly marked upon the butt end of each log by the collector.  The north side of each log will also be marked.

When only one bolt from a tree is used it will be designated by the number of the log from which it is cut.  Whenever more than one bolt is taken from a tree, each 4-foot bolt or length of trunk will be given a letter (mark), a, b, c, etc., beginning at the stump.

All bolts will be sawed into 2-1/2” X 2-1/2” sticks and the sticks marked according to the sketch, Fig. 50.  The letters N, E, S, and W indicate the cardinal points when known; when these are unknown, H, K, L, and M will be used.  Thus, N5, K8, S7, M4 are stick numbers, the letter being a part of the stick number.

[Illustration:  FIG. 50.—­Method of cutting and marking test specimens.]

Only straight-grained specimens, free from defects which will affect their strength, will be tested.

Care of Material

No material will be kept in the bolt or log long enough to be damaged or disfigured by checks, rot, or stains.

Green material:  The material to be tested green will be kept in a green state by being submerged in water until near the time of test.  It will then be surfaced, sawed to length, and stored in damp sawdust at a temperature of 70 deg.F. (as nearly as practicable) until time of test.  Care should be taken to avoid as much as possible the storage of green material in any form.

Air-dry material:  The material to be air-dried will be cut into sticks 2-1/2” X 2-1/2” X 4’.  The ends of these sticks will be paraffined to prevent checking.  This material will be so piled as to leave an air space of at least one-half inch on each side of each stick, and in such a place that it will be protected from sunshine, rain, snow, and moisture from the ground.  The sticks will be surfaced and cut to length just previous to test.

Order of Tests

The order of tests in all cases will be such as to eliminate so far as possible from the comparisons the effect of changes of condition of the specimens due to such factors as storage and weather conditions.