98 Mr. H. Tomlinson. The Influence of 



Experiment VI. — Platinum-silver Wire. 



Number of vibrations 

 per second.* 



Remarks. 



259 -7x1 

 254-7 x 2 

 253 9x3 



"Wire free except at botb ends. 

 Wire clipped in the centre. 

 "Wire clipped at a point one-tbird of 

 the whole length from one end. 



Let 1c be the equivalent shortening of the wire when it is free 

 except at the two ends ; then since the velocity of sound along the 

 wire will be the same in all three cases we must have : — 



and 



From (1) we obtain h = 0*0255, 



and from (2) k = 0*0250. 



The mean of these two values of Tc is 0'02525, and since the length 

 of the wire examined was 553*85 cm., the velocity of sound in centi- 

 metres per second obtained from the three sets of trials given in 

 Experiment VI will be 280,440, 280,380, and 280,500 respectively, 

 with a mean of 280,440 and a probable error of only 0*008 per cent. 



Experiment VII. — Silver Wire. 

 Length, 553*85 cm. 



Number of vibrations 

 per second. 



Remarks. 



253-8x1 

 253-1x2 

 253 -0x3 



"Wire free except at both ends. 

 "Wire clipped in the centre. 

 "Wire clipped at a point one-third of 

 the whole length from one end. 



Adopting the same mode of procedure as before we obtain for h the 

 two values 0*00366 and 0*00354 with a mean of 0*00360. Thus the 



* The numbers gh en under this heading are in this and the next experiments the 

 mean values resulting from several closely accordant trials. 



