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.