[ 8o 9 ] 
CX. Of the Irregularities in the Motion of a 
Satellite arifng from the fpheroidical Fi- 
gure of its Primary Planet : In a Fetter 
to the Rev. James Bradley D. D. Aft ram- 
mer Royal , F. R. S. and Member of the Roy- 
al Academy of Sciences at Paris ; by Mr. 
Charles Walmefley, F. R. S. and Member 
of the Royal Academy of Sciences at Ber- 
lin, and of the Inftitute of Bologna. 
Reverend Sir, 
Read Dec. 14, OINCE the time that aftronomers have 
; 5 k3 been enabled by the perfection of their 
inflruments to determine with great accuracy the mo- 
tions of the celeftial bodies, they have been folicitous 
to leparate and diftinguifh the feveral inequalities dis- 
covered. in thefe motions, and to know their caufe 
quantity, and the laws according to which they are 
generated. This feems to furnifh a Sufficient motive 
to mathematicians, wherever there appears a caufe 
capable of producing an alteration in thofe motions, 
to examine by theory what the refult may amount 
to, though it comes out never fo fmall : for as one 
can feldom depend Securely upon mere guefs for the 
quantity of any effeCt, it mull be a blameable ne- 
glect entirely to overlook it without being previously 
certain of its not being worth our notice. 
Finding therefore it had not been con fr Wed what 
effcCt the figure of a planet differing from that of a 
Fol. 50. y L Sphere 
