198 Mr. C. Coleridge Fair. Some Expressions for 



slight alteration of the expressions for Z is necessary; those for X 

 remain the same. 



It has been thought sufficient for numerical application to give 

 dP*/d@ to three places of decimals. The establishment of the fourth 

 place would involve a considerable amount of extra labour. Though 

 dP.JdO, dPJdQ, and dPJdB are not used in the present work, they have 

 been calculated in order to complete the table as far as it goes. 



