APPENDIX B 



APPENDIX B 



APPARATUS FOR MEASURING THE ABSORPTION OF WATER BY A 

 GIVEN AREA OF ANY SURFACE OF A PIECE OF WOOD. 



A piece of round tool-steel is bored with a hole having a transverse 

 area of i cm. One end is bevelled to a cutting edge and the other 

 screwed to take a cap within which is an indiarubber washer. The 

 cap is provided with a hole through which a graduated pipette can 

 be passed. The pipette is inserted through a small hole in the 

 rubber washer thus making a water-tight joint. The rubber washer 

 also serves to make the cap water-tight with the steel body. 



To apply the apparatus, drive the sharp end of the body into the 

 surface of the wood to be examined, fill it with water and cover with 

 the washer and cap. Insert the pointed end of the pipette through 

 the holes in the cap and washer and allow the water to rise in the 

 glass tube until it reaches zero, and note the time The water 

 will rise in the tube because it is displaced by the glass tube, 

 which forces it out of the body. At first a rapid sinking takes 

 place as the water fills the ruptured pores upon the surface of 

 the wood. This soon slows off and the natural pace of absorption 

 is soon reached. For this reason it is useful to watch the fall of 

 the level of the water in the pipette carefully for a quarter of an 

 hour, otherwise a false impression will be obtained. Do not allow 

 the steel to remain longer in the wood than is absolutely necessary, 

 for if tannin be present the cutting edge will rapidly perish. 



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