426 



NATURE 



{August 15, 1878 



'■'Las Junia, Col., July 29. 

 " Good observations of the eclipse at Las Junta. Com- 

 plete set of photographs. " Asaph Hall " 



" Crefon, W. T., July 29 

 " Sky cloudless and observations perfectly successful. 

 Six photographs of corona. Four polariscope photo- 

 graphs of corona and a fine drawing obtained. No ultra 

 violet spectrum visible during totality. 



"W. HARKNESS" 



" Cenlml City, Col., July 29 

 " Whole eclipse perfectly observed. I find no Vulcan 

 as large as sixth magnitude. Hastings finds consistent 

 tangential polarisation. Drawings and photographs of 

 corona. Diffraction shade bands observed. 



"E. J. HOLDEN" 



'^ Separation, W.T., July 2<^ 

 "Observations here very successful. Saw wings of 

 light, supposed to be zodiacal light, extending 6° on each 

 side of the moon in the direction of the ecliptic. Com- 

 mander Sampson, U.S.N., found no dark lines in con- 

 tinuous spectrum of corona. Line 1,474 seen near sun's 

 limb. ISl o bright lines visible a few seconds after totality. 



"S. Newcomb" 



" Pik^s Peak, Col, July 29 

 "Fair weather after a week's storm. Observations 

 successful in a marvellously clear sky. Corona resem- 

 bling zodiacal light followed in one direction twelve dia- 

 meters from the sun. " S. P. Langley." 



" Eclipse successfully observed at Dallas, Texas. All 

 four contacts satisfactory. No inter-Mercurial planet 

 seen with comet-seeker. ' Thin clouds. No stars seen 

 near the sun. Corona very brilliant. Several drawings 

 secured and photographs taken. " D. P. Todd " 



It is telegraphed to the Tribum from — 



" Havana, July 30.— Yesterday the total echpse of the 

 sun was visible in this latitude. The sky was perfectly 

 clear, and complete observations were made. A report 

 of the results obtained was expected to-day, but the 

 scientific commission which took observations at Mariel, 

 where the meridian passes, has not returned yet." 



" Quebec, July 30.— The eclipse of the sun yesterday 

 was witnessed under the most favourable circumstances." 



'■'■Washington, July 30.— The Signal Service Observer 

 at Virginia City, Mont., reports to the Chief Signal 

 Officer as follows : — ' Our four telescopic stations have 

 got all the contacts nicely, and three sketches of the 

 corona.' ' ' 



OUR ASTRONOMICAL COLUMN 



The Saturnian Satellite Hyperion.— The fol- 

 lowing ephemeris of Hyperion is deduced from the 

 elements which were calculated by Prof. Asaph Hall, 

 upon his observations in 1875 with the Washmgton 

 26-inch refractor. 



At Greenwich Midnight. 



Position. Distance. 



93 



37 



36 



93 

 146 

 189 

 218 

 228 

 216 

 181 



The plane of the orbit of the satellite is assumed to coin- 

 cide with that of the ring, and as the earth has passed 

 through the plane since the period included by the 



ephemerides which appeared in this column last year, 

 the apparent motion of the satellite is now reversed, or 

 the angles of position diminish. The above ephemeris 

 includes an entire revolution of the satellite, and will 

 serve, if necessary, to afford an idea of its position at any 

 time during the present opposition, remarking that the 

 satellite will be at its peri-saturnium at the following 

 times: August 15 '0939, September 5*4052, September 

 267165, October i8'0278, and November 8"339i. 



Olbers' Star near y Pegasi.— On September 27, 1820, 

 Olbers rem arked a star of 6 7 m. not entered upon Harding' s 

 map, and which Harding had not seen during two com- 

 parisons of it with the heavens. It was somewhat 

 brighter than 39 and nearly equal to 40 Piscium. Olbers 

 accounted for it not having been observed on the 

 meridian by the fact of its culminating within a few 

 seconds of y Pegasi. He watched it during the 

 remainder of the season without noticing any change in 

 brightness, and it was from the circumstance of his 

 attention being thus directed to this quarter of the sky 

 that he made an independent discovery of the comet of 

 1821. The star is in the Durchnusterung as 7*5 m., 

 and was observed once by Argelander (October 24, 1861), 

 the resulting position for 1855-0 being R.A. oh. 5m. 41 -Ss., 

 N.P.D. 73° 52' 56". Bessel did not observe it, but it is 

 suspicious that he has a star 9m. only, preceding Arge- 

 lander' s position of Olbers' star 7-05. and 3' 58" to the 

 north, where the Durchmusterung has no star. It is a 

 case for some one of those observers who are occupied 

 with the variable stars to explain. 



LETTERS TO THE EDITOR 

 [The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to return, 

 or to correspond with the writers ef, rejected manuscripts. 

 No notice is taken of anonymous communicati0ns. 

 [The Editor urgently requests correspondents to keep their letters at 

 short as possible. The pressure on his space is so great that it 

 is impossible otherwise to ensure the appearance even of com- 

 munications containing interesting and novel facts. 1 



A New Mineral 



Mr. Barnett, of Chyandour, near Penzance, sent to the 

 British Museum some time ago a mineral which appears to be 

 new. 



It is white with a slight tint of blue or greenish blue, and 

 occurs as a layer sometimes of a quarter of an inch thickness, 

 generally of a uniform fibrous structure, lining hollows or encas- 

 ing quartz and other minerals. It is associated with earthy 

 chlorite and quartz ; iron pyrites, some copper pyrites, and mis- 

 pickel being disseminated in the lode-material. Scorodite in boss- 

 like aggregations also occurs with it, and in at least one instance 

 the interior of the bosses of scorodite is filled with the mineral 

 in question. . 



Dr. Flight has analysed it, and, though the mode m winch 

 the water is present has to be established more certainly, the 

 general result of the analysis may be stated to be the assigning 

 to the mineral a formula expressed, in " old style," as 



3R2O3, AS2O6 + 16H2O, 

 RoOi representing alumina with a notable amount of ferric 

 oxide. The tint seems due to about one per cent, of copper, 

 and a small amount of a sulphate is also present. The presence 

 of the sulphate and general character of the composition would 

 lead one to place the mineral with Pitticite, or "iron-sinter." 

 But the formula, as Dr. Flight has pointed out, is so nearly that 

 of an arsenical (instead of a phosphatic) Evansite that the true 

 place of the mineral seems to be near the Evansite of David 

 Forbes I propose to call it Liskeardite, and to describe it 

 more precisely hereafter. N. S. Maskelyne 



British Museum, Mineral Department, 

 August 12 



The Colouring of Birds' Eggs 



Within the last few months several notices have appeared 

 in both England and Germany of supposed newly-discovered 



