368 



Astronomical and Nautical Collections. 



plement, h the half sum of the distance and both altitudes, and 

 h — s the same half sum diminished by the altitude of the 

 apposite luminary. 



Correction of the Oblique Semidiameter . 



For example, taking h zz 32°, h — s=:2\°, and rf = 44°, as 

 in Sect. IV., we have 93 + 55 + 16 rr 164, whence it appears 

 that the correction is much less than a second ; and if h — 82^, 



