593 



registered in the General Reports should be compared with those 

 originally noted in the Field- or, as they are called, Angle-Books of 

 the department. 



3rd. There certainly has been one error, if not more than one, 

 committed in the computations ; but where such error or errors exist 

 it is impossible to say priori : the only decisive mode of detection 

 must consist in a thorough recomputation. 



4th. All the celestial observations for amplitude made by Colonel 

 Lambton were reduced many years ago ; but I need hardly point 

 out that the constants and formulae for aberration, precession, nutation, 

 &c., have undergone vast alterations since that period, and of course 

 corresponding recomputations would now be necessary. This would 

 not have been needed if the observations at each limit of the Arc of 

 Amplitude had been made simultaneously by two instruments on the 

 same set of stars, one instrument at each limit, as has been done in 

 the two Arcs north of Damargida ; but it becomes of importance when 

 not only the years, but the seasons of observations were different. 



If this were effected, we should at least have the satisfaction of 

 knowing that the most had been made of the late Colonel Lambton's 

 operations, which indeed might fairly rank with those of MM. 

 Bouguer and De la Condamine, or MM. Maupertius, Clairaut, and 

 others, though, from the inferiority of instruments and other causes, 

 of course they could not be classed for accuracy with those of a more 

 modern date. 



In proper time and place I have abundance to say on this subject ; 

 but it will be evident that the revision and recomputation here sug- 

 gested constitute a task beyond the power of any individual, and 

 are indeed a state affair, which, now that India and all belonging to it 

 has been taken under the control of Her Majesty's Government, can 

 only be accomplished as other state concerns usually are. 



What, therefore, I venture to recommend is, that the President and 

 gentlemen of the Council of the Royal Society should take this sub- 

 ject into their consideration, as a national question falling peculiarly 

 under their superintendence, and that in their capacity as the parent 

 Society and leading scientific body of Great Britain, they should use 

 their influence to have such measures effected as in their judgment 

 may seem meet. 



Perhaps a recommendation from the Royal Society to the Secretary 



VOL. XI. 2 U 



