xiii. ABSTRACT OF PROCEEDINGS. 
Dr. A. R. Walker was proposed for ordinary member- 
ship by Mr. Gurney, seconded by Mr. Smith. 
Prof. Richards exhibited (a) specimens from the lead- 
silver lode at Indooroopilly, which had been presented to 
the Queensland Museum; and (b) a specimen of white 
marble from Eulam, near Rockhampton. ‘The stone is 
coarse grained, of good colour, and should be of considerable 
mural value. 
The President exhibited a specimen of the lizard 
Diplodactylus hilliit, Longman, from Mungana, Chillagoe 
Line, North Queensland. Previously this species had only 
been known from a single specimen collected at Port Darwin. 
Professor R. W. H. Hawken, B.A., M.E., M- Inst. C.E., 
read a paper on “‘ The Strut Problem.” 
The author examined :— 
(1) The original mathematica] deduction for central 
loading by Euler. 
(2) The modified mathematical result for eccentric 
loading by Prof. R. H. Smith. 
(3) The problem as it appears in Engineering Design, 
where the strength of the material is an important 
factor. 
(4) The exact result deduced by R. W. Burgess. 
The ‘resilient’ effect er ‘Euler Value’ the author 
assumes as a maximum unit load, and that any other load 
may be considered a fraction of the unit load, in this way 
the mistakes and inconsistencies of the many proposed 
formulae may be shewn; and curves have been drawn 
which enable stress conditions to be examined for all 
loads. 
The author examines, and reconciles, the apparently 
inconsistencies of the results of (1) and (2), and shews also 
that the result (4) which, deduced from an exact equation, 
at first sight appears to shew (1) and (2) inaccurate, has 
a definite explanation which proves his previous deductions 
to have been justified. 
The President, Prof. Richards, and Mr. Wilson 
contributed to the subsequent discussion. 
