266 Vibration of the Gravest Mode of a Thin Rod. 



Thus for any rod, tapsring to a section of finite depth, its 

 period of vibration should be given, with a possible error of 

 about 6 per cent., by the Rayleigh curve corresponding to that 

 assumption, which gives the lower result for the value of c/l 

 under consideration. 



Fig. 4. 



Graph of (l+ ^[j-Me J J /(J " hi Q 



The term in /x 4 independent of co and the coefficient of X 

 have be engraphed against c/l for the two different assumptions 

 as to the deflexion curve (see figures 3, 4), so that it should 

 be easy to see which assumption will give the better result 

 for any particular value of c/l or X. 



In conclusion the author would like to express her grati- 

 tude to Mr. Arthur Berry for much kind advice and helpful 

 criticism. 



