1824.] Analyses of Books. 143 



calculated by one computer for forty pounds : it is not likely, 

 therefore, to be far from correct, if we say that for forty pounds 

 more than are at present expended, the daily corrections might 

 be procured, done by two separate computers, and consequently 

 entitled to every possible confidence. 



Having shown what would be the benefits which would result 

 from such a publication ; having pretty well ascertained what 

 would be the expence of procuring it ; it only remains to see, 

 how far the former are equivalent to the latter : — the task is easy. 

 To place the British observer on an equal footing with the 

 foreign, is worth something; — to induce individuals to the study 

 of practical astronomy, is surely worth something; — to enable 

 travelling astronomers to multiply observations, and to prove the 

 accuracy of those they make, is certainly worth something ; — to 

 afford facilities to the examination of published observations, is 

 doubtless worth something; — to entail accuracy in the reduction of 

 the most important observations, is unquestionably worth some- 

 thing; — and to save an immensity of labour is indisputably worth 

 something. What may be the individual value of the advantages 

 just enumerated, it is needless to inquire ; but taken collectively, 

 I hesitate not to say, that it is equivalent at least to ten times the 

 sum which need be spent in procuring it. 



Hence I can come to the conclusion, " That the daily correc- 

 tions in right ascension and north polar distance of the 46 zero 

 stars, should be published annually at the public expence." 



Bkckman.strcct, Jan. 29, 1824. JAMES SOUTH. 



Article XIX. 

 Analyses of Books. 



Philosophical Transactions of the Royal Society of London, for 



1823. Part II. 



(Continued from p. 63.) 



XVI. An Account of an Apparatus on a peculiar Construction 

 for performing Electromagnetic Experiments. By W. H. Pepys, 

 Esq. FRS.— (See Annals, N. S. v. 392.) 



XVII. On the Condensation of several Gases into Liquids. By 

 M. Faraday, Chemical Assistant in the Royal Institution. 

 Communicated by Sir H.Davy. (See the present number, p. 89.) 



XVIII. On the Application of Liquids funned bu the Conden- 

 sation of Gases as mechanical Agents. By Sir Humphry Davy, 

 Bart. Pres. RS. 



" The elasticity of vapours in contact with the liquids from 

 which they are produced under high pressures by high tempera- 

 tures, such as those of alcohol and water," observes the Presi- 



