386 



Mr. A. Mallock. Some Measures of [Mar. 19, 



drops back to its equilibrium position, on the removal of the force, still 

 more rapidly, but little further permanent set being produced. 



On again increasing the force so as to exceed that first applied, a 

 further gradual extension, lasting a considerable time, takes place ; 

 and additional permanent set is found when the force is removed. 



Diagram (11) shows that 



(1.) The immediate elastic bending and the permanent set are pro- 

 portional in amount to the force causing them. 



(2.) That the increment of extension or deflection which happens 

 in time is something like a constant quantity. 



The method, however, described in this paper is not well adapted to 

 the investigation of these phenomena, as the state of strain in the 

 beam on which they depend varies from + through to on 



