Show SELECTING WOODS Not cry long lone a ago o timber was selected select select- ed entire entirely according to its external appearance Tho The diameter and len length th of the piece the straightness s of grain r un sometimes the weight ht sufficed to do de termine both its commercial value and its destination At that time on account account ac ac- ac count of the difficulty of tion tion woods of local origin were almost exclusively employed It is very dif ferent forent nowadays s With the increase in consumption and the tho decrease in the local production production tion of wood it has bec become me arY to transport timber of every ariet variety and of many places of ori origin in Furthermore Furthermore Further Further- more moro the diversified ai industries of the present dB day require a corresponding diversity di di- in the tho wood employed For one ono purpose the important quality is 18 bardness hardness bard hard ness for another elasticity for or a third ease case of working or resistance to attack attack attack at at- tack b by external a agencies It is eident evident evi i dent that very different qualities arc are required red for an au umbrella handle a barrel stave a billiard cue cue a carriage c frame ct etc The Tho hand ma magnifying glass which was first employed has ceased t to suffice suf suf- fice flee for the exact determination of tho the structure of the wood Tho The compound microscope is now used for tho the minute and careful examination of longitudinal longi and transverse sections of ofa a specimen of til timber tho the commercial value and the proper industrial employment em om of which it is desired d to de de- de- de termine Fine grain rain and thick walled cells assure the solidity and which are arc required in carpentry and these arc tiro incompatible with an deuce dance of tissue filled with starch starch Scientific American |