200 ■ ON THE 



18. As the mean- obliquity of the ecliptic,, and. the quantities, of its di- 

 minution, can only be deduced with accuracy from a great number of ob* 

 servations of the apparent obliquity taken at different times, .and places, 

 and at considerable intervals ; I shall not detain the reader with this last 

 reduction, but present this paper to astronomers in Europe, as an in- 

 gredient which may be combined with others, for the resolution of this 

 important problem.; being at the same time in hopes, that the advantage 

 which I have had of observing between the tropics, may balance the in- 

 accuracies which (notwithstanding the utmost care in taking the altitudes) 

 may have crept into my observations. 



anuHMjjg E MWi M i j q iran 



Of the Latitude of the Madras Observatory., deduced from 100 observations 



of the Sun's Meridional Altitude. 



19. These observations are given in the tables at the end, with the 

 respective elements which have served for obtaining the latitude. The 

 mean limit of the results is 6. The power of the instrument may there- 

 fore be taken at 3 on each side of the mean, and any observation diverg- 

 ing by more than double that quantity on either side, (6) may justly be 

 rejected' as affected by some error, independant of the instrument. This 

 I have done in the course of the present series. 



20. It will appear remarkable, that the mean latitude derived from 

 100 unobjectionable observations, (48 of which were taken when the sun 

 was either on or near the zenith) should give the latitude of the ob- 

 servatory by 7 43 less than the stars. This difference is further con- 

 firmed by 16 observations of the sun., taken with the zenith sector at 

 different times at the observatory. What follows will shew the com- 

 parison. 



