Astronomical Society. 457 



t:iating ; the mind swells in their contemplation, and attains in their 

 pursuit, an expansion and a hardihood which fit it for the boldest 

 enterprize. — But the direct practical utility of such labours is fully 

 worthy of their speculative grandeur. The stars are the land-marks 

 of the universe ; and amidst the endless and complicated fluctuations 

 of our system, seem placed by its Creator as guides and records, 

 not merely to elevate our minds by the contemplation of what is 

 vast, but to teach us to direct our actions by reference to what is 

 immutable in his works. It is indeed hardly possible to over-ap- 

 preciate their value in this point of view. Every well-determined 

 star, from the moment its place is registered, becomes to the as- 

 tronomer, the geographer, the navigator, the surveyor, — a point of 

 departure which can never deceive or fail him, — the same for ever 

 and in all places, of a delicacy so extreme as to be a test for every 

 instrument yet invented by man, yet equally adapted for the most 

 ordinary purposes ; as available for regulating a town clock, as for 

 conducting a navy to the Indies ; as effective for mapping down the 

 intricacies of a petty barony, as for adjusting the boundaries of 

 transatlantic empires. When once its place has been thoroughly 

 ascertained and carefully recorded, the brazen circle with which 

 that useful work was done may moulder, the marble pillar totter 

 on its base, and the astronomer himself survive only in the grati- 

 tude of posterity : but the record remains, and transfuses all its 

 own exactness into every determination which takes it for a ground- 

 work, giving to inferior instruments, nay even to temporary con- 

 trivances, and to the observations of a few weeks or days, all the 

 precision attained originally at the cost of so much time, labour 

 and expense. 



To avail ourselves of these records, however, we must first have 

 the means of disentangling the observed places of the stars at any 

 moment, from the regularly progressive effect of precession, and 

 from a variety of minuter periodical inequalities arising from the 

 nutation of the earth's axis, and from the aberrationof light, of which 

 the genius of theoretical, no less than the industry of practical, as- 

 tronomers has at length succeeded in developing the laws, and 

 fixing the amount, so as to leave little probability of any material 

 change being induced by future researches. 



The calculations, however, required for this purpose, if instituted 

 for each particular star at the time it is wanted, are so numerous 

 and troublesome as to become a very serious evil ; the effects of 

 which have been severely felt in Astronomy in the discouragement 

 it has offered to the reduction of observations, owing to which the 

 labour of many an industrious observer's life has been in great mea- 

 sure thrown away. Indeed, a lamentable picture might be drawn 

 of the waste of valuable labour traceable to this cause. The want 

 of tables therefore to facilitate the reduction of particular stars was 

 early felt. I shall not, however, enter into any historical detail of 

 the attempts hitherto made from time to time to supply this desi- 

 deratum. A well drawn up and concise account of them is given in 

 Mr. Baily's Preface to the Catalogue, which renders superfluous all 

 I could say on the subject. Indeed, useful as they have been, and 



New Series. Vol. I. No, 6. June 1827. 3 N con- 



