76 ADAMSON MACHINE. 



specimen due to a load of 3 Ib. at the end of this lever 

 being 



1 5,000 x 3 = 45,000 Ib. 



Hung from the lever is a floating weight B, which is 

 traversed along the lever by a cord actuated by a small 

 hand wheel. This weighs 4 Ib., and at the furthest 

 point which it is allowed to reach in running along the 

 team it is equivalent to 48,000 Ib. So that with the four 

 3 Ib. weights, each equivalent to 45,000 Ib., in all, 180,000 Ib., 

 and the floating weight, equivalent to 48,000 Ib., the 

 machine is at its full capacity of 

 180,000 + 48,000 = 228,0001b. or rather more than 100 tons. 



The floating weight, as it moves outwards, traverses a 

 graduated scale on the beam. On this scale the main 

 divisions register 1,000 Ib. each ; there are also subdivisions 

 indicating 20 Ib. each. 



When a test is to be commenced the floating weight is 

 placed at zero, and there are no weights on the scale plate. 

 To increase the load the floating weight is traversed out- 

 wards until a load of 45,000 Ib. is reached. It is now run 

 back to zero and a 3 Ib. weight hung on the scale plate. 

 The floating weight is moved outwards again until another 

 45,000 Ib., or a total of 90,000 Ib., has been reached. It is 

 now run back to zero, and a second 3 Ib. weight hung on to 

 the scale plate ; and so on to the end of the test. 



It will be seen that the total weight applied when at the 

 full load is only 16 Ib. The designer of the machine, the 

 late Mr. Daniel Adamson, contended that by using a 

 multiple-lever machine of high power, very small working 

 weights are required, a machine of great sensitiveness 

 secured, and by having the individual levers of fairly large 

 fulcrum distance, the errors due to inaccurate knife-edge 

 measurements are reduced to a minimum. 



In addition to its use for tension tests, the machine can 

 be used for compression, bending, and punching tests, by 

 the addition of a few extra parts. 



Besides the four levers, which have already been men- 

 tioned, a fifth is sometimes added, not for load measure- 

 ment purposes, but simply to serve as a pointer, and to 

 enable the operator to detect more quickly and more easily 

 differences of load on the specimen. Such a one is shown 

 in the figure. 



In order to protect the levers and knife-edges from 

 dust and dirt and injury, the whole of the right-hand end 

 of the machine is enclosed and the upper part covered 



