THEORY OF STATISTICS. 
Frequency Curves. 
For the early classical memoirs on the normal curve or law of error 
by Laplace, Gauss, and others, see Todhunter’s History (Introduction : 
ref. 7). The literature of this subject is too extensive to enable us to do 
more than cite a few of the more recent memoirs, of which 6, 7, and 13 
are of fundamental importance. The student will find other citations 
in 6, 8, and 14. 
(2) CuARLIER, C. V. L., ‘‘Researches into the Theory of Probability” 
(Communications from the Astronomical Observatory, Lund); Lund, 
1906. 
(3) CuxNiNGHAM, E., “The o-Functions, a Class of Normal Functions 
occurring in Statistics,” Proc. Roy. Soc., Series A, vol. 1xxxi., 1908, 
p- 310. 
(4) EpcEwoRTH, F. Y., ‘On the Representation of Statistics by Mathema- 
tical Formule,” Jour. Roy. Stat. Soc., vol. 1xi., 1898 ; vol. Ixii., 1899 ; 
and vol. Ixiii., 1900. 
(5) EpcEwortH, F. Y., Article on the ‘‘ Law of Error” in the Encyclopedia 
Britannica, 10th edn., vol, xxviii., 1902, p. 280. 
(6) EpcEworrn, F. Y., ‘The Law of Error,” Cambridge Phil. Trans., vol. 
xx., 1904, pp. 36-65, 113-141 (and an appendix, pp. i-xiv, not 
printed in the Cambridge Phil. Trans.). 
(7) EpcEworrH, F. Y., “The Generalised Law of Error, or Law of Great 
Numbers,” Jour. Roy. Stat. Soc., vol. 1xix., 1906, p. 497. 
(8) EpcEworTH, F. Y., “On the Representation of Statistical Frequency by 
a Curve,” Jour. Roy. Stat. Soc., vol. 1xx., 1907, p. 102. 
(9) FECHNER, G. T., Kollektivmassichre (herausgegeben von G. I. Lipps; 
Engelmann, Leipzig, 1897.) 
(10) KAPTEYN, J. C., Skew Frequency Curves in Biology and Statistics ; 
Noordhoff, Groningen ; Wm. Dawson & Sons, London, 1903. 
(11) MACALISTER, DONALD, ‘‘ The Law of the Geometric Mean,” Proc. Roy. 
Soc., vol. xxix., 1879, p. 367. 
(12) N1xow, J. W., ‘“An Experimental Test of the Normal Law of Error,” 
Jour. Roy. Stat. Soc., vol. 1xxvi., 1913, pp. 702-706. 
(13) PEARsoN, KARL, ‘Skew Variation in Homogeneous Material,” Phil. 
Trans. Roy. Soc., Series A, vol. clxxxvi., 1895, p. 343. 
For the generalised binomial machine, see § 1. The memoir deals 
with curves derived from the general binomial, and from a somewhat 
analogous series derived from the case of sampling from limited 
material. Supplement to the memoir, 4bid., vol. cxevii., 1901, p. 443. 
For a derivation of the same curves from a modified standpoint, 
ignoring the binomial and analogous distributions, ¢f. Chap. X., 
ref. 18. 
(14) PEARsoN, KARL, ‘‘Das Fehlergesetz und seine Verallgemeinerungen 
durch Fechner und Pearson”: A Rejoinder, Biometrika, vol. iv., 1905, 
. 169. 
(15) Pio Luict, * Nuove Applicazioni del Calcolo delle Probabilita allo 
Studio dei Fenomeni Statistici e Distribuzione dei Matrimoni secondo 
Eth degli Sposi,” Mem. della Classe di Scienze morals, etc., Reale 
Accad, dei Lincet, vol. x., Series 3, 1882. 
(16) SEEPPARD, W. F., “On the Application of the Theory of Error to Cases 
of Normal Distribution and Normal Correlation,” Phil. Trans. Roy. 
Soc., Series A, vol, cxcii., 1898, p. 101. (Includes a geometrical treat- 
ment of the normal curve.) 
(17) YULE, G. U., “On the Distribution of Deaths with Age when the Causes 
of Death act cumulatively, and similar Frequency-distributions,” 
214