1834.] Catalogue of Moon-Culminating Stars. 95 



precede and two to follow the moon: that the stars thus forming each pair be chosen 

 so as not to be very distant from each other in right ascension, and nearly midway 

 between the right ascension of the moon at the time of her transit on two conse- 

 cutive days: that the two stars chosen to follow the moonon onedaybeadoptedas the 

 two to precede the moon on the subsequent day : that no star be selected below the 

 5th, but on no account below the 6th, magnitude : that the stars so chosen should 

 not be situated more than five degrees from the path of the moon's true orbit : and 

 that the list should be continued through each lunation within four days of the new 

 moon: that the apparent right ascension (in time) of the star to two places, and the 

 mean declination of the star to the nearest minute, be given." 



In the first place, those stars recommended by the council are intend- 

 ed for universal use, and as being the most likely to be visible in ordi- 

 nary states of the weather in places having variable climates. The 

 number of these stars seem to me to have been selected with reference 

 to fixed observatories, wherein a few observations being made on each 

 night of every lunation for a considerable interval of time,would even- 

 tually assign the difference of longitude between them with the utmost 

 accuracy: whereas, those in India, with one exception, may be aptly 

 called flying observatories. It has seemed to me to be desirable that we 

 should be enabled to determine the difference of longitude of these, in the 

 shortest interval of time; and therefore, for this reason, and from the 

 consideration that the climate will interpose no serious obstacle to their 

 being observed, I have inserted those stars which are so expressly 

 repudiated by that report. 



Another motive for forming this extended catalogue has arisen from 

 this consideration, that those stars inserted in the Nautical Almanac 

 have been selected with regard to observatories wherein astronomers or 

 their assistants are expected to spend their nights, and who, therefore, 

 are supposed to endure no pain and to forego no pleasure to be prepared 

 to make those especial observations at all hours ; whereas, with the 

 exception already referred to, observers here have other duties of a civil, 

 political, or military nature to fulfil, and may, therefore, however willing, 

 be unable at all times to attend at the proper hour of the night to 

 make those observations, and those correlative ones whereby the error 

 of their time-pieces, and the deviation of their instruments from the 

 meridian, may be determined. 



For these reasons, and for others, which will easily suggest themselves, 

 I have ventured to draw up the accompanying extended catalogue ; but from 

 which it will be observed, that the interval of time necessary to devote 

 to the transit will seldom exceed one hour. If, however, gentlemen 

 would observe those stars which are inserted in the Nautical Almanac, 

 and which I may have omitted, they would essentially promote our geo- 

 graphical knowledge in India, as their observation, combined with those 



