452 Kevie-jos, and Notices respecting New Books. 



lated a set of Tables that comprehend quantities even too minute 

 to be generally serviceable in practical astronomy." 



The addition of Bessel's Tables, as also of Carlini's, with the Ta- 

 bles computed from the elaborate formula of Mr. Ivory ; also of 

 Littrow's and Zach's modifications of Bessel's Tables, — seems to 

 have been an after-thought on the part of our author : yet in doing 

 this he has adhered to his original determination of sparing no trouble 

 in making his collection as complete as possible. 



We come next to another set of the most important Tables, 

 These are the Tables from I. to XIV. inclusive, originally pro- 

 posed by Baron Zach, and reduced to their present shape by the 

 late Mr. Fallows. They are arranged in two sets, the first contain- 

 ing the corrections in right ascension, and the rest the corrections 

 in north polar distance for precession, aberration, lunar nutation, 

 and solar nutation. 



Table XV. contains the proportional parts of the annual preces- 

 sion, so as to give the correction for any given day of the year. — 

 Tables XVI. and XVII. are for the purpose of giving the sun's 

 longitude correctly at the moment of the culmination of any known 

 star ; for as the aberration and solar nutation are both functions of 

 the sun's longitude, neither will be obtained correctly unless this 

 longitude be accurately known at the instant of observation. Table 

 XVI. gives this; and Table XVII. gives it also with still greater 

 accuracy. But this last Table also answers another purpose, viz. 

 that of adapting the sun's longitude, calculated for one observatory, 

 to the meridian of any other. 



The labour bestowed on Table XVIII. must have been very con- 

 siderable. We will refer to the author's own account of this "Table, 

 given in page 322, and so leave it with our scientific readers 

 to appreciate its merits. We need only observe, that although to 

 an "expert mathematician" there would be no difficulty \a com- 

 puting these numbers, yet having them computed for him, saves 

 him a great deal of trouble ; and therefore it is not only to those 

 "who are not skilled in trigonometrical calculations" that this Ta- 

 ble is useful, but to every practical astronomer. This Table con- 

 sists of 45 pages ; and we will readily take our author's word for it, 

 that they "have been calculated at the expense of considerable la- 

 bour." 



The next Tables in the collection are the universal Tables of 

 Delambre, which, from the facility with which they can be applied 

 to single observations, our author has thought proper to introduce. 



After these follow a few small Tables, called Differential Tables, 

 the object of which is to give by inspection the changes which take 

 place in the aberration and lunar nutation, when a small alteration, 

 such as one degree, is given to the place of a star in right ascension 

 or declination ; and also two other Tables, the former tor correcting 

 the diurnal aberration, and the latter for determining the aberration 

 of light in the case of a comet or planet. 



The next scries of Tables is of a different kind, inasmuch as the 

 corrections to be taken from them do not result from physical 



