108 Experiments upon Hardwoods of Australia. 



made upon scantlings of unusual size — viz., 14 feet 8 inches 

 between bearings — the breadth and depth ranging from 10 \ 

 inches by 7 inches to 11 J inches by 8 J inches. The specific 

 gravity, elasticity, and transverse strength were tested, very 

 full particulars as to the deflection being given. These 

 experiments are of great value, on account of the large size 

 of the pieces tested. 



Tredgold. — These are taken from Tredgold's Carpentry, 

 edition of 1875. The information is stated to have been 

 furnished by Mr. Josiah Atwool, at one time resident in New 

 South Wales. The information refers to the specific gravity 

 and transverse strength of three timbers only, no particulars 

 being given as to how the experiments were carried out. 



Laslett. — Mr. Laslett is the author of a work termed Timber 

 and Timber Trees, and, when this was written, was timber 

 inspector to the Admiralty. This work is one of the most 

 valuable treatises devoted to timber yet published. In it 

 the author discusses a very great variety of British and 

 foreign woods, and gives details of numerous experiments 

 which he has carried out. Many of the colonial timbers come 

 under his notice, and he applies to them in most cases their 

 true designation. Four to six experiments were made on 

 each variety, the scantlings being 6 feet between bearings 

 and 2 inches square for transverse, 2 inches square for tensile, 

 and various-sized cubes for crushing tests. The specific 

 gravity, elasticity, tensile, transverse, and crushing strengths 

 were tested. Where comparison can be made, the results 

 arrived at by Mr. Laslett are very generally in accord with 

 those of other experimenters, tensile strengths excepted, for 

 which he gives much lower values. The length of the pieces 

 tested for transverse strength is stated to have been 7 feet, 

 but only 6 feet between bearings. Now, in calculating the 

 values of E. and S., Mr. Laslett has unfortunately taken the 

 length as 7 feet, thereby arriving at incorrect conclusions. 

 This is to be regretted, as the error is embodied in the 

 tables, to which one naturally turns for information of the 

 kind. Observing this discrepancy, I have calculated afresh 

 the values of E. and S. for all cases to which I have found it 

 necessary to refer. 



Mueller. — These experiments are taken from the Eucalyp- 

 tographia. They were carried out by Baron von Mueller 

 and Mr. Luehmann. The scantlings were 2 feet long and 

 2 inches square. The specific gravity, elasticity, and trans- 

 verse strength were tested for twelve different species. 



