ABSTRACT OF PROCEEDINGS. XIX. 



2. " Some Physical Properties of Nickel Steel," by W. H. Warren, 

 Wh. Sc, M. Inst. c. E., Challis Professor of Engineering, and 

 S. H. Barraclough, m. M.E., Assoc. m. Inst. C.E., Lecturer in 

 Mechanical Engineering, University of Sydney. 



Nickel steel, hitherto employed chiefly in the manufacture of 

 armour plates, and to a less extent, in forgings for certain impor- 

 tant parts of machinery, will probably have a greatly extended 

 use as its physical properties become better known, and the cost 

 of its production lessened. The present paper describes a series 

 of tests of specimens of three varieties of nickel steel manufactured 

 by the firm of Fried. Krupp, of Essen, Germany, the three varie- 

 ties being known as 'mild,' 'medium,' and 'non-rusting,' and con- 

 taining respectively, three, eight and twenty-five per cent, of 

 nickel. After summarising the present state of our knowledge 

 of the material, the authors describe their experiments to deter- 

 mine the tensile and compressive strengths, limit and coefficient 

 of elasticity, percentage elongation and contraction of area, yield 

 point, torsional strength, shearing strength, and relative liability 

 to corrosion. Detailed tables of the observations for each experi- 

 ment accompany the paper, and, in order to supply a basis for 

 comparison, especially as regards the elastic limits, a summary of 

 results obtained from similar tests of specimens cut from a Vicker's 

 axle is attached. 



NOTES AND EXHIBITS. 



Professor Anderson Stuart, m.d., University of Sydney, 

 exhibited a preparation of the human ear showing a new mode of 

 demonstrating the action of the auditory ossicles. The method 

 consists in removing the roof of the tympanic cavity so as to fully 

 expose its contents. A glass tube is now tied into the external 

 auditory meatus. To this tube is attached a rubber tube about a 

 foot long, and through these tubes the demonstrator by his mouth 

 can force air into, and suck air out of, the external meatus. Thus 

 the tympanic membrane is made to move, carrying with it the 

 ossicles in the same sort of movement as in the normal action of 

 the parts, the only essential difference being that this movement 



