444 



SECTION 12. APPLIED MECHANICS. 



SOUTH GALLERY. GROUND FLOOR, ROOMS B. C. 



I. -PROPERTIES OF MATERIALS. 



21'/a. Machine for Testing the Strength and Duc- 

 tility of Metals. Sir Joseph Whitivorth. 



The cylinder, pump, ram, and head are made of Whitworth's fluid com- 

 pressed steel, so as to obtain the maximum of strength with the ininimum of 

 weight. 



The machine is designed to test cylinders of one half a square inch in area, 

 and it registers up to 100 tons per square inch. 



217b. Cast Hoop of Whitworth's Fluid Compressed 

 Steel. Sir Joseph Whitworth. 



Strength as cast and compressed, 28 tons per square inch. 



Strength when forged, 40 tons per square inch. 



Ductility as cast and compressed, 18 per cent. 



Ductility when forged, 30 per cent. 



A hoop or ingot of the fluid metal while under pressure is shortened about 

 \ of its length. 



A portion of the hoop exhibited has been turned to show the nature of the 

 metal. 



42 8b. Pieces of Steel Cylinders, torn by traction in expe- 

 riments made to ascertain the influence of mode of treatment on 

 the mechanical properties of steel. 



Imperial Technical Society, St. Petersburg. 



Annexed is a report on the experiments. Out of a block of unforged soft 

 cast steel were cut, in identical positions parallel to the axis, 16 bars which 

 were treated under heating or forging in eight different manners, two samples 

 in each way. The samples were then turned to the shape of cylinders for 

 tensile proof, and elastic and permanent elongations for each of them deter- 

 mined for a series of increasing tensile forces, density, hardness (by inden- 

 tation), and other elements. Results indicated in annexed diagrams and 

 tables. 



42O. Cement Testing Apparatus, for ascertaining the 

 tearing strain of Portland and other cements, in sections of Ij 

 square inches. Originally designed for the Metropolitan Board 

 of Works. Press for removing bricks from mould ; and Moulds 

 for making test bricks. Patrick Adie. 



