242 



SCIENCE 



[Vol. V., No. 111. 



such observations, we reproduce Dr. Ball's 

 diagram representing his present series of ob- 

 servations on the assumption of his finally de- 

 duced parallax, 0".4676. If this is the star's 

 true parallax, it cannot affect the observed 

 declinations to a greater extent than (y.40, 

 which is the maximum length of the ordinates 

 in the curve. The large black dots indicate 

 the observations, while the curve shows at 

 every point the calculated effect of parallax. 

 Of the discrepancies between the two, Dr. Bali 

 remarks, that though some of them "seem 

 large, relatively to the total amount to be 

 measured, yet the greatest divergence of the 

 observation from the curve is not more than 

 the angle subtended by a penn} T -piece at the 

 distance of fifteen or twenty miles." 



Of Groombriclge 1618, a star remarkable 

 for its proper motion, we need only say that 

 the parallax resulting from an elaborate series 

 of observations is 0".322 ± 0".023 ; and, of 

 the star (P iii. 242) suggested by Struve as 

 suitable for a parallax series, that Dr. Ball 

 finds its parallax inappreciable. Of the star 

 6 Cygni (B), however, more should be said, as 

 comparison with 61 (B) Cygni shows both stars 

 to be binary s}stems, with a large proper 

 motion common to both, and color and magni- 

 tude substantially identical. Dr. Ball's inves- 

 tigations point to a parallax of 0".482 ± 

 0'.054, so that to the other features of re- 

 semblance of the two sj-stems we are to add 

 the fact that the two objects appear to be 

 equally distant from the solar system. 



The parallax determinations of Dr. Gill 

 and Dr. Elkin at the Cape of Good Hope 

 are, without doubt, the most thorough and ac- 

 curate work of the kind ever performed. The 

 heliometer was not a large one, having an 

 aperture of only four inches, and the interval 

 of time set aside for the accomplishment of 

 their programme was but eighteen months. 

 It was considered essential that several of the 

 parallaxes should be investigated independently 

 b}' both observers, and with different compari- 

 son-stars, in order to obtain some test of the 

 general accuracy of the conclusions reached ; 

 and, after much consideration and trial, the 

 following stars were finally selected : a Cen- 

 taitri, Sirius, and elndi, for observation b}' 

 both Gill and Elkin ; Lacaille 9352, o. 2 Eridani, 

 and (3Centauri, for observation b} 7 Gill alone ; 

 and £Tucanae, eEridani, and Canopus, for 

 observation by Elkin alone. In Science, vol. 

 iii. p. 456, attention has alread}^ been called to 

 the results of these investigations, and the re- 

 markable degree of precision attained in the 

 measurements. Eveiy source of error of which 



it seems possible to conceive was most care- 

 fully considered, and terms for the elimination 

 of such errors were suitably introduced into 

 the equations of condition representing all the 

 observations. The observers express their 

 entire confidence, which must be shared by 

 every one who critically examines their work, 

 in the degree of exactitude which is indicated 

 mathematically by their final results. All in- 

 terested in the progress of stellar astronomy of 

 precision will be glad to know that the impor- 

 tant conclusions and suggestions in the memoir, 

 with regard to future extended work in the same 

 fields, are now to be put to the practical test 

 by Dr. Gill and Dr. Elkin conjointly. 



David P. Todd. 



NOTES AND NEWS. 



Among the prizes awarded at the annual meeting 

 of the French academy on the 23d of February were 

 the following: the Francoeur prize, to Mr. Emile 

 Barbier; a prize of six thousand francs, for the prog- 

 ress in efficiency of naval forces, was divided between 

 the hydrographic mission to Tunis, and Mr. Baills for 

 a work on artillery (' Traite de balistique rationelle ' ). 

 Other prizes were given to Messrs. Manen and Ha- 

 nusse (mechanics) ; to the Swiss engineer Kiggenbach, 

 the Monthyon prize, for his mountain railways ; to 

 Mr. Hoiiel, the Poncelet prize, for his various contri- 

 butions to pure mathematics; to Mr. du Rocher du 

 Quengo, for his improvements in screw steam navi- 

 gation; to Mr. Radau, the Lalande prize, for his 

 memoir on diffractions; Mr. Ginzel, the Yalz prize, 

 for a paper on secular acceleration of the moon's 

 motion ; to Mr. G-. Cabanellas, for his theory of the ap- 

 plication of electricity to the transmission of power; 

 Mr. Durand-Claye, for his researches on the diffusion 

 of typhoid-fever; Mr. Chancel, for his work on the 

 acetones; Messrs. Gustave Cotteau and Emile Riviere 

 (geology); Messrs. Otto Lindberg, G-. Sicard, L. 

 Motelay, and Yendryes (botany); Mr. P. Fischer 

 (zoology); Drs. Testut, Cadet de Gassicourt, and 

 Leloir (medicine and surgery); Mr. Tourneux (em- 

 bryology); Messrs. Cadiat and Kowalevski in anat- 

 omy; Messrs. Jolyet and Laffont in experimental 

 physiology; Capt. H. Berthaut and Jules Girard in 

 physical geography; Mr. Marsaut, 1,500 francs, for 

 his investigations of safety-lamps for miners; Mr. 

 de Tastes, for his work in meteorology; Mr. Yalson, 

 the Gegner prize, for his work in mathematics and 

 physics; Dr. Neis, for geographical explorations; 

 Dr. J. Boussingault, for applied chemistry. The 

 Breant prize of a hundred thousand francs for 

 cholera researches was not awarded. 



— The following account of unusual phenomena 

 was received March 10, at the Hydrographic office, 

 Washington, from the branch office in San Fran- 

 cisco. The bark Innerwich, Capt. Waters, has just 

 arrived at Yictoria from Yokohama. At midnight 



