PROCEEDINGS. 231 



The following letter was read from Professor Riicker : — 



Savile Club, 107 Piccadilly, W., 



November 21st, 1887. 

 Dear Professor Liversidge. 



It is generally assumed that in the Northern Hemisphere rocks 

 which affect the direction of the declination magnet attract the North Pole. 



This would of course be the case with a mass of soft iron one extremity 

 of which was deeply imbedded iu the earth. The earth's magnetism 

 would induce a south-seeking pole in the upper end which would attract 

 the north-seeking pole of a magnet in its neighbourhood. 



In the Magnetic Survey of the United Kingdom on which Dr. Thorpe 

 and I have been engaged, we have in several instances observed this effect. 



I am not however aware as to whether the truth, of the supposition has 

 ever been tested in the Southern Hemisphere. If not I think it would 

 be worth attention. 



I should therefore be very glad if you could obtain for me any 

 information as to whether rocks in Australia which contain (1) magnetite 

 (2) iron ore other than magnetite attract the souih-seeking pole of a 

 magnet in their neighbourhood. 



I am, very truly yours, 



AETHUE W. EUCKEE. 



Mr. D. M. Maitland stated that some years ago while in the 

 Tumut district he found the southern end of the magnetic needle 

 attracted by magnetic ore in the ground. 



Professor Warren, M. Inst. C.E., then exhibited and described 

 the Autographic Stress-strain Diagram-drawing apparatus, as 

 used at the University of Sydney in recording the results of testing 

 materials in tension, compression, and cross-breaking. The 

 usefulness of the apparatus was explained at some length, and a 

 quantity of interesting information was given. It was stated that 

 the machine would pull from L K). to 100,000 lbs. The Professor 

 showed the manner in which the apparatus is used in recording 

 the results of testing the transverse strength and elasticity of 

 beams of iron and timber • the results of testing iron and timber 

 columns ; and the results of testing the tensile strength and 

 elasticity of all materials. • A cordial vote of thanks was accorded 

 to the Professor for the interesting description he had given of 

 the apparatus. Professor Warren, in reply, said he would have 

 the machine in working order at the Sydney University on the 

 5th of September next, the date on which the Society's biennial 

 conversazione will be held. This reunion will take place in the 

 Great Hall of the University. 



The following donations were laid upon the table and 

 acknowledged : — 



Donations Received during the Month of July, 1888. 

 (The Names of the Donors are in Italics.) 

 TEANSACTIONS, JOUENALS, EEPOETS, &c. 

 Adelaide — Eeport on the Progress and Condition of the 



Botanic Garden during the year 1887. The Govt. Botanist. 



