ERRATA to No. XXII. 



The Reader is requested to pass over the demonstration given in § 1 4, as it is erroneous. 

 Another demonstration of the almost self evident proposition enunciated in § 14 is given in 

 § 29, page 423. : in which place, instead of the words : — "Also by Art. 14," (7th line from 

 top) read the following words : — " Also since the maximum extent of the vibrations of the 

 material particles must be small compared with that of the etherial, for the reasons assigned in 

 Article 14." 



CORRECTIONS to No. XXIII. 



Since the publication of the above Paper, a mistake has been pointed out to me by the 

 Rev. J. Power, in p. 440. The three equations at the bottom of this page are not independent, 

 and therefore the proposition which is the subject of the latter part of this, and of the first 

 paragraph of the following page, is not generally true for motion in three dimensions. In 

 the cases however of motion in two dimensions, and of motion symmetrical about an axis, 

 the three analogous equations are reduced to one, and the proposition is true. None of the 

 succeeding results are affected by this error, excepting that the first paragraph of p. 448 must 

 be restricted to the two cases above mentioned. There also occur the following errata:— 



P. 440 1. 3 for C read C,. 



P. 442 1. 13 for x read J~l y. 



P. 445 1. 2 from bottom, insert the terms - -r — -t-j- dx- -,— -j-j- dy, on the left-hand 



side of the equation. 



G. G. STOKES. 



