to the Method of Least Squares. 199 



1854 Helfe. Menioire sur la prohahilite clu tir des projectiles de 

 V artillerie navale. Paris, 4to. — Second ed., 1856, 8vo. 



1855 Baciie. ' ComparisoTi of the reduction of horizontal angles 

 by the methods of dependant directions and of dependant angular 

 quantities, by the method of least squares.' Rep. Coast Survey U. S. 

 for 1854, pp. 6:]*-70.* 



The first method is shown to possess a slight advantage. 



1855 Bertrand. ' Methode des momdres carres. llemoires sur la 

 combinaison des observations., par Ch. Fr. Gauss. Paris, 8vo, pp. 167. 



This volume renders quite accessible the Latin memoirs of Gauss. 



It contains translations of pages 208-220 of the llteoria nwtus 



1809, pages 20-26 of Disquisito de Ralladis, 1811, and the 



whole of the memoirs of 1816, 1822, 1823, 1826 and 1827. The me- 

 moirs of 1823 and 1827 form the bulk of the book, the others being 

 added at the end as " Notes." 



1855 Bertrand. 'Sur la raethode des moindres carres.' Comptes 



Rendus Acad. Paris, Vol. XL, pp. 1190-1192. 



Historical and critical remarks made on presenting a copy of the 

 above book to the Paris Academy. 



1855 Gerling. ' Ueber die Schatzung des mittlern Fehlers di- 

 recter Beobachtungen.' Archiv Math. u. Phys., Vol. XXV, pp. 

 219-222. 



Contains three pages of corrections and errata to his book (1843). 



1855 Gould. 'Report containing directions and tables 



for the use of Peikce's Criterion for the Rejection of Doubtful Obser- 

 vations.' Rep. Coast Survey XT. S. for 1854, pp. 131*-138* 



Reprinted with a different title in Goukrs Astron. Jour., 1855, 

 Vol. IV, pp. 81-87. 



1855 HiLGARD. 'Discussion of the probable error of observation 



with a twenty-six inch portable transit ' Rep. Coast Sur. 



U. S., for 1854, p. 121*. 



The probable error is given as ±0.072®. 



1855 LiAGRE. ' Siir la probabilite de I'existence d'une cause 



d'erreur reguliere dans une serie d'observations.' Pull. Acad. Pel- 



f/iqiie, Vol. XXII, Pt. II, pp. 9-13, 15-54. 



A valuable theoretical discussion illustrated with practical exam- 

 ples. 



