THE AUSTRALIAN GREY MANGROVE. 



267 



"The wood is valued on account of its durability under water, 

 and as a fuel for heating furnaces. It is preferred to other kinds 

 of wood on the West Coast of India." — ( Pharmographia Indica, 

 Vol. in, p. 82,— Dymock). 



"Timber said to be durable as poles and in other places used 

 for ship-building, etc." — (The Forests and Forest Cape Colony, p. 

 287,— Sim). 



"In New South Wales, the wood is valued for stone-mason's 

 mallets, on account of its toughness." — The Treasury of Botany " 

 Vol. I, p. 112,— Lindley and Moore). 



The timber of the Australian tree may be described as a 

 pale coloured, very hard, heavy, cross laminated timber, 

 inclined to slightly darken on exposure. It has several 

 characteristics that easily differentiate it from any other 

 timber known to me, and these are here described in 

 sequence (infra). It is used in New South Wales for knee 

 boats, crooks, and generally in boat-building when strength 

 is required. 



I am indebted to Mr. H. J. Swain, b.a., b.Sc , Lecturer, 

 Mechanical Bngineeering Department, Sydney Technical 

 College, for the following tests: — 



No. 



Material. 



Size. 



Area of 



Cross 



Section. 



Breaking 



Load in 



lbs. per 



sq. in. 



Modulus of 



rupture in 



lbs. per 



sq. in. 



Modulus of 

 elasticity in 



lbs. per 

 square inch. 



Bate of 

 Load in 

 lbs. per 

 minute. 



1 



Grey 

 Mangrove 



3-03" 



X 



3-03" 



X 



36" 



9-18sq.in. 



6610 



12850 



168000 



3860 



2 



Grey 

 Mangrove 



3-02" 



X 



3-03" 



X 



36" 



915 „ 



6620 



12900 



169000 



4000 



3 



Grey 

 Mangrove 



3-02" 



X 



3-03" 



X 



36" 



9-15 „ 



7070 



13800 



172500 



4000 



For comparison the averages of three specimens were — Ironbark 

 9000; Blue Gum 5000; Burma Teak 6000; Colonial Teak 8000. 



