248 



TIMBER 



the weight of this sample was 70 Ibs. per cubic foot ; a 

 sample paving block weighed 64^ Ibs. per cubic foot. Under 

 a compressive test a piece 10 ft. long and 8*98 inches X 8'90 

 inches = 79'92 square inches crushed under a total load of 

 380,100 Ibs. = 4,756 Ibs. per square inch ; the weight of 



' -Photo 



FIG. 35. Crushing Tests of Tasmanian Blue Gum. 



this sample was 71| Ibs. per cubic foot. Fig. 35 shows the 

 peculiar twisting of the fibres of blue gum under com- 

 pressive stress. These samples stood about 2^ tons per 

 square inch. One sample is particularly noticeable where 

 the timber has opened so clean and sharp as to look like a 

 mortice. A piece of blue gum scantling 146 ft. long and 



