I. PROPERTIES OF MATERIALS. 445 



42Oa. Michele's Patent Cement Testing Machine. 



De Michele, Rochester. 



The block to be tested is placed in the jaws prepared to receive it ; the handle 

 is then turned, which raises the weighted lever by exerting a pull on its short 

 end through the medium of the cement block. When the leverage is so in- 

 creased as to exert a force too great for the cement to sustain, it breaks, and 

 the lever falls, leaving the index-pointer at the spot to which it had been 

 raised. The arc along which the pointer moves is graduated to show in 

 number of pounds the tensile stress applied. A suitable arrangement, when 

 the cement block breaks, prevents the lever from falling more than half an 

 inch. 



These machines are now in general use, nearly one hundred of them having 

 been sent to different parts of the world. They are principally used by the 

 leading royal and civil engineers in this country, and by a large number of 

 contractors and cement manufacturers. 



42Ob. Drawings of Machines and Apparatus for testing 

 Materials. Charles Jenny > Vienna. 



Five sheets of drawings, representing : 



1 . Machine for testing, [by means of traction and pressure, the elasticity 



and rigidity of materials. 

 The machine of the Imperial Institute was constructed by C. Faff, Vienna. 



2. Machine for testing materials. Werder's system constructed for testing 



elasticity and flexional rigidity. Executed by the Machine Factory 

 Company, Kell & Co., Nuremberg. 



3. Machine for testing materials. Werder's system. Constructed for test- 



ing 'the torsional elasticity and rigidity. Executed by the Machine 

 Factory Company, Kless & Co., Nuremberg. 



4. Machine and apparatus for ascertaining and determining the elasticity 



and rigidity of wire, leather straps, thin ropes, &c. 



Executed in the former workshops of the Imperial and Royal Polytechnic 

 Institute. 



5. Optical apparatus for determining the modulus and the limits of elasticity 



by the application of the results obtained on tensile and compressive 

 force, flexural elasticity, and rigidity. 



The original apparatus of the Imperial Polytechnic Institute were constructed 

 by G. Starke and Kammerer, mechanicians, Vienna. 



426. Thurston's Testing Machine, invented by Professor 



Thurston, of Steven's Institute of Technology, Hoboken, U.S.A. 



W. ff. Bailey and Co., Manchester. 



This machine is used for testing the limit of resistance, ductility, and honio- 

 geneousness of iron, brass, steel, and other materials of construction. By 

 means of an ingenious but simple arrangement, a permanent diagram of the 

 behaviour under varying conditions of the materials can readily be obtained. 



423. Apparatus for determining the elasticity, tensile 

 strength, and columnal strength of woods and timber. 



Prof. Dr. Nordlinger, Hohenhcim, Wurtemberg. 



42 3a. Apparatus used for experimenting on the 

 Flexural and Torsional Rigidity of Solids, by Professor 

 Everett, and described in the " Transactions of the Royal Society," 

 1866, p. 185. Sir William Thomson. 



