94 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



Summary of Compression Tests of Pit-prop Timber — continued. 



From the above averages and those of the earlier tests 

 already published, a table has been compiled giving the mean 

 crushing strengths of the more important species of Scottish- 

 grown wood arranged in order of their strength. 



In comparing these results with those obtained from the 

 foreign pit -props, the Finnish white wood result must be 

 neglected, as only one prop of this class of wood was sent for 

 testing, and it is very inadvisable to assume that the result of 

 this single test is any close approximation to the average 

 strength of Finnish white wood. The Finnish red wood result, 

 4025 lbs., on the other hand, being an average of five tests, the 

 figures for which varied between 2963 and 4569 lbs., may be 

 taken as a fair average of this quality of pit-wood. 



