260 Dr. Lees and Mr. Grime on a Compact Apparatus 



Description of the Apparatus. 

 The wire was supported rigidly in an iron frame AB (fig. 2) 

 by two clamps 0, D whose distance apart could be adjusted 



Fig. 2. 



by means of the nuts E, F. These were adjusted till the 

 tension in the wire was rather more than that necessary to 

 straighten it when unloaded. In order to be able to reproduce 

 this stace of tension readily in successive experiments, a 

 subsidiary ware half the length of the one experi- 

 mented on, and cut from the same piece, was Fig-. 3. 

 suspended vertically and loaded at the lower end 

 (fig. 3) till the note it gave on being plucked with a 

 pointed brass wire was identical with that given 

 by the wire experimented on when held at its centre 

 and plucked in the same way. The accuracy of 

 the determination of T by this method was not, 

 however, sufficient to admit of its being used in nEp 

 equation (1) to determine e, and equation (2) was jj 

 therefore used throughout. 



The load was applied at the centre of the length 

 of the wire by means of a very small hook of steel \ 

 wire, from which a scale-pan could be suspended. \J 

 The vertical descent of the hook was measured by a 

 Brown & Sharp micrometer screw-gauge with apitchof *5 mm., 

 and head graduated in '01 mm., admitting of estimation 

 down to *001 mm. The screw-stop in the lower jaw of the 

 screw-gauge was removed to allow the wire suspending the 



