60 The Rev. Brice Bkonwin on the Theory of Planetary Disturbance. 



Let V be the longitude on tlie fixed plane, measured from its intersection 



with the sliding plane, 



y^ = r sin y, 



the rest as before ; then, by substitution, 



sin V = cos i ] cos/ sin (w + Snt) + sin/ cos (tt + Snt) \ - s sin i. 



Or, 



sin )' = cos t sin (/+ -n + Qnt) — s sin i. ( 7 ) 



This will give the longitude when / is large ; and when it is small, we can 

 without difficulty find v itself without finding its sine. 



I must, in conclusion, repeat what I have before said, that I think this trans- 

 formation worthy of consideration. 



GUNTHWAITE HaLL, 

 NEAR BaRNSLET, YoKKSHIKE, 



Nov. 13, 1848. 



