Errata in No. 331 . 



Page 281, line 12 should read :— 



o' = B 2 /i 2 +B 4 /u 4 +...+&c. 



Page 316, lines 6, 7 should stand :— 



- 400 k 

 -3T ' 





And dele line 8. 



4 5 

 = 533 miles. 



Just published, price Is., post free Is. bd. 

 THE CALENDAR OP THE ROYAL COLLEGE OF SURGEONS 



for 1875. 

 Taylor and Francis, Red Lion Court, Fleet Street, E.C. 



In a few days, price 2s. 6d., post free 3s. 

 THE UNIVERSITY COLLEGE CALENDAR. 



The CALENDAR for 1875-76, containing the Bye-laws, Regulations, Memo- 

 rials, List of Students, Exhibitioners, &c, together with much useful information 

 respecting the College and School. 



Taylor and Francis, Red Lion Court, Fleet Street, E.C. 



Third Edition. Price Is., post-free Is. Id. 

 A MANUAL OF THE BAROMETER. 



Containing an Explanation of the Construction and Method of using the Mer- 

 curial Barometer, with appropriate Tables for Corrections for Temperature, and 

 Rules for obtaining the Dew-point and the Heights of Mountains ; also, a De- 

 scription of the Aneroid Barometer. 



By JOHN HENRY BELVILLE, 



of the Royal Observatory, Greenwich. 



Taylor and Francis, Red Lion Court, Fleet Street, E.C. 



The Annals and Magazine of Natural History. 



Including Zoology, Botany, and Geology. — Monthly, price 2s. 6c?. 



Complete sets (in Numbers) may be obtained at the following prices : — 



The First Series, in 20 volumes, from 1838 to 1847. Price £6. 



The Second Series, in 20 Volumes, from 1848 to 1857. „ £9. 



The Third Series, from 1858 to 1862, Vols. I. to X. „ £5. 



1863 to 1867, Vols. XL to XX. „ £6. 



Taylor and Francis, Red Lion Court, Fleet Street, E.C. 

 THE LONDON, EDINBURGH, AND DUBLIN 



Philosophical Magazine and Journal of Science. 



A Journal devoted to Physics, Astronomy, Mechanics, Chemistry, Mineralogy, 

 and the Allied Sciences. Monthly, price 2s. 6d. 



Complete sets (in Numbers) may be obtained at the following prices : — 



A set of the First Series, from 1798 to 1826 (wanting a few plates ), in 68 

 volumes. Price «j£15. 



The Second Series, from 1827 to 1832, in 1 1 volumes. Price £2 4s. 



The Third Series, in 37 volumes, from 1832 to 1850. „ £6. 



Taylor and Francis, Red Lion Court, Fleet Street, E.C. 



[ADVERTISEMENTS continued on 3rd page of Cover. 



