242
��|Voi_ v.. Ko. lit
��such observation a, we repixKluce Dr. Ball's diagram representing his present aeries of ob- aei'vations on the asstiinption of hia finally de- duced parallax, 0".4G7(j. If this ia Ihe star's true parallax, it cannot affect the observed declinations to a greater extent than 0".40, which is the maximum length of the ordinatcs in the curve. The large black dots indicate the observations, while the curve shows at every point the calculated effect of parnllu?;. Of the discrepancies between the two. Dr. Ball 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 cnrve is not more than the angle subteiidrd by a penny-piece at the distance of fifteen or twenty miles."
Of Groombridge 1G18, a atar remnrkable for its proper motion, we need only say that the parallax reaulting (Vom an elaborate series of obaervations is C^'.322 ± 0".02a; and, of the star (P iii. 242) snggested 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 compariaon with 61 (B) Cygni showa both atara to be binary systems, with a lai^e proper motion common to both, and color and ui^ni- tude substantially identical. Dr. Ball's inves- tigations point to a parallax of 0".482 ± .054, 80 that to the other features of re- semblance of the two systems we are to add the fact that the two objects appear to be equally distant fVom the solar system.
The parallax determinations of Dr. Gill and Dr. Elkin at the" Cape of Good Hope are, without doubt, the moat thorough and ac- curate work of the kind ever performed. The heliometer was not a lai^e 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 by both observers, and with different compari- son-stars, in order to obtain some test of the general accuracy of the conchisiona reached; and, after much consideration and trial, the following stars were finally selected: a. Cen- tauri, Sirius, and cindi, for observation by l>oth Gill and Elkin; Lacaille 9352, o,Eridani, and ff Ccntanri. for observation by Gill alone; and t'Tucanae, eEridani, and Canopus, for observation by Elkin alone. In Science, vol. iii. p. 45G, attention has already been called to the results of these investigations, and the re- markable degree of precision attained in the measurements. Every source of error of which
��it seems possible to conceive was most fully considered, and terms for the climinnti of such errors were suitably introduced i the equations of condition representing all observations. The observers express the entire confidence, which must be shared every one who critically examines their wc in the degree of exactitude which is indical mathematically by their final results. All iiP terested in the progress of stellar astronomy of precision will be glnd to know that the impo^ taut conclusions and suggestions in the memoir, with regard to future extended work fields, are now to be put to the practical by Dr. Gill and Dr. Elkin conjointly.
D*vtD P. To(
��NOTES AND NEWS.
��rop^l
��Among the prizes awarded at the annual meeling of the French academy on the 2:)d of Pebruarj were the following: the Franco«ur prize, to Mr. Emile Barbiar; a prize of six thousand franca, for the prog- ress in efflcleucy of naval forces, was divided belweeu the hydrographic miBSion to Tunis, and Ur. Bulls for n work on artillery ('TraitSdebalJBlique rfttioiielle ' I. Oilier prizes were given U> Uesars. Manen aoil Hk- luiBse (mechanics); to the Swiss eo^neer Rlggeiibacb, the Monthyon prize, for his mountain railways; lu Mr. Hoiiel, the Poncelet prize, for liis various conlri- bntions to pure malheniatlcB; to Mr. da Rocher du Quengo, for his improvements in screw steam navi- gallon; to Mr. Rtulau. the Lalande prize, for hi* memoir on diffractions; Mr. Ginzel, the Vatz prize, for a paper on secular acceleration of the moon's motion; taJS.r. G. Cabanellas, for his theory of the^i- plication of electricity to the transmission of power; Mr. Durand-Claye, for his researclies on the diffusion of typholcl-fever; Mr. Chaucel, for his worit on the BceUines; Messrs. Gustave Cotteau and Emile Rivlfare (geology); Messrs. Otto Lindberg, G. Sicanl, L. Motelay, and Vendrjfes (botany); Mr. P. Fischer (zoology); Drs. Tostul, Cadet de Gasslconrt, atid Lelolr (medicine and surgery); Mr. Tourneux (em- bryology); Messrs. Cadiat and Eo wale vsbi in anat- omy; Messrs. Jolyet and LafEont in experimental physiology; CapL H. Bcrthaut and Jules Qlrard la physical geography; Mr. Marsaut, 1,500 franca, for his Investigations of safety-lamps for miners; Mr. de Tastes, for bis work in meteorology; Mr. Yatson. the Ci^uer prize, for bis work in mathematics and physics; Dr. Nels, for ge<^raphlcal exptomiions; Dr. J. Bonsslngault, for applied chemistry. The Br^nt prize of a hundred thousand francs for cholera researches wan not awarded.
— The following account of unusual phenomena was received March 10, at the Hydrographlc office, Washington, from the branch office In Han Fran- cisco. The bark Innerwich, Capt. Waters, has jurt arrived at Victoria from Yoiiohama. At midni^'
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