to the Method of Least Squares. 193 



Herschel's proof is discussed and regarded as unsatisfactory. 

 Laplace's method is also explained and defended. The paper is very 

 interesting and valuable. See Glaisher, 3Iem. Astro?i. ISoc. Lond., 

 1872, Vol. XXXIX, pp. 112-113 ; also below 1851 Donkin. 



1850 HossARD and Poudra, ' Seconde Tlieoreme de minimum 

 pour un sy Sterne de droite dans I'espace.' JSfouv. Ann. 3Iath., Vol. 

 IX, pp. 241-242. 



On the centre of gravity of a system of points. See also Vol. VII, 

 p. 407 and 454. 



1850 Paucker. Der mittlere Fehler zweiter Ordnung. Arbeit 

 Kurland. Gesell, Vol. VIII, pp. 104-112. 



185(> Verdam. '• Verhandelliig over de niethode der kleinste quad- 

 raten.'' Groningen, Vol. I, 4to, pp. xxi, 409. 



I have not seen Vol. II of this work and find no direct reference to its 

 jDublication : it was probal)ly published about 1 853. Vol. I is devoted 

 to the practical features of the nietliod and Vol. II to the theory. 



Vol. I assumes the principle of Least Squares and develops the 

 methods of adjustments and comparison by probable errors, weights, 

 etc. Numerous well chosen ])ractical examples are given worked out 

 in detail. The work abounds in historical information, and is the 

 most complete text-book on the subject which has come to my notice. 



1851 Airy. 'On a Question of Probabilities which occurs in the 

 use of a fixed collimator for the Verification of the Constancy of 

 Position of an Azimuth Circle.' Rep. Brit. Assoc, for 1850, pp. 1-2. 



Is it justifiable to use the Theory of Errors in finding the probable 

 errors of quantities which are partly results of observation and partly 

 deductions of formulae? 



1851 Airy. ' On the Weights to be given to the separate Results 



for Terrestrial Longitudes, determined by Observations of Transits 



of the Moon and Fixed Stars.' 3Iem. Astron. Soc. Lond., Vol. XIX, 



pp. 213-229. 



Weight is defined as " the reciprocal of the square of the probable 

 error." The paper discusses nine practical cases. 



1851 Denzler. ' Ueber den Fundamentalsatz der Methode der 

 kleinsten Quadrate.' Mittheil. Gesell. Zilrirh.^ Vol. II, pp. 110-118. 

 Appears to be of little importance. 



1851 DoNKix. ' On certain Questions relating to the Theory of 

 Probabilities.' Lond. Phil. Mag., Vol. I, pp. 353-368, 458-466 ; Vol. 

 II, pp. 55-66. 



Trans. Conn. Acad., Vol. IV. 25 Oct., 187 7, 



