20 



NATURE 



\_Nov. 7, 1889 



region, it is impossible to see such as these now found with an 

 aperture much less than that of the Lick telescope. A list is 

 therefore given of the principal communications to astronomical 

 periodicals relating to the alleged discovery of faint stars in the 

 trapezium of Orion. 



Barnard's Comet, 1888-89. — Comptes rendus. No, 17, 

 October 21, 1889, contains some observations made by MM. 

 Rayet and Courty of the motion of Barnard's comet, the posi- 

 tions of the comparison stars being also given. The series of 

 observations extend from September 11, 1888, to September 27, 

 1889. 



Biographical Note on J. C. Houzeau.— M. A. Lan- 

 caster, the collaborator with Houzeau of the most comprehensive 

 bibliography extant, has proved himself, in this note, to be 

 the most capable of writing his deceased friend's biography. 

 Houzeau's scientific and literary labours cover an extensive 

 field : astronomy and geodesy, mathematics and meteorology, 

 geology and geography, are all represented in his works ; and 

 when but a young man, he directed the triangulation of his 

 country. In politics Houzeau was an enthusiast, and whilst in 

 America, about 1861-69, he gave a considerable amount of atten- 

 tion to the subject of the emancipation of the slaves, and wrote 

 numerous and important articles upon it. In 1875, Houzeau 

 completed a series of astronomical and meteorological observa- 

 tions made at Jamaica, and in the following year was appointed 

 Director of the Brussels Observatory. His crowning work — the 

 "Vade Mecum of Astronomy," was finished in 1882. It repre- 

 sented the work of a lifetime, and as a guide to astronomers is 

 invaluable. Such a compilation, however, calls for continual 

 additions, and a general bibliography was published in 1887, 

 ■with the assistance of M. A. Lancaster. This was Houzeau's 

 last work, but before his death, on July 12, 1888, he earnestly 

 expressed the wish that it should be carried on by his colla- 

 borator. Houzeau's life was full of vicissitudes, and his biography 

 is most interesting. 



The Karlsruhe Observatory.— The third volume of the 

 Publications of the Grand-Ducal Observatory of Karlsruhe has 

 recently been published by Dr. W: Valentiner, the Director. 

 The bulk of the volume is by Dr. E. von Rebeur-Paschwitz, and 

 ■consists, first, of a series of measures with the 6-inch refractor of 

 the two star-clusters M. 35 and M. 25 ; secondly, of a discussion 

 of the orbit of Comet Wells, 1882 I., and the derivation of 

 definitive elements ; and lastly^ of auxiliary tables for the com- 

 putation of parallax for 169 different observatories. 



Dr. Boy Mattheissen adds a short paper on the orbit of Comet 

 Denning, 1881 V. 



The volume contains three plates, the first two being maps of 

 the star-clusters under observation.rwhilst the third gives photo- 

 graphs of the same two clusters as taken by Dr. E. von Gothard 

 at Hereny. 



Objects for the Spectroscope. 



Sidereal Time at Greenwich, at 10 p.m. November 7 = ih. 9m. 9s. 



Remarks. 



(i) Dr. Huggins notes that the spectrum ends abruptly in the 

 orange. Maxima of brightness have since been recorded by 

 myself at, approximately, 468-474, 517, and 546, and the latter 

 two have also been confirmed by Mr. Taylor. Further con- 

 firmation is required. For comparison, a Bunsen or spirit-lamp 

 flame will be found convenient for the first two, and the brightest 

 fluting seen when lead chloride is introduced into the flame for 

 the third. Mr. Lockyer suggests that since the central conHen- 

 sation is probably at a higher temperature than the surrounding 

 portions of the nebula, different parts of the nebula should show 

 differences in their spectra. Observing with Mr. Lockyer's 30- 

 •inch reflector at Westgate-on-Sea, on October 20, I suspected 



some change in the spectrum away from the nucleus, but was 

 unable to complete the observation on account of clouds, and 

 have not since had an opportunity of repeating it. 



(2) The bright lines most constantly seen in the spectrum of 

 this star are C, F, and D3, but their appearance is somewhat 

 irregular. Continuous observations, with special reference to 

 the relative intensities of the lines, are suggested. The lines are 

 well seen in a lo-inch equatorial with a Maclean spectroscopic 

 eye-piece. Bright fluting-^ of carbon have also been suspected, 

 and comparisons should be made with the Bunsen or spirit- 

 lamp to confirm these. The continuous spectrum should also be 

 carefully examined for maxima, b, D, and other absorption- 

 lines, have also been recorded. 



(3) This is a star which gives a spectrum of dark flutings 

 fading away towards the red. Duner records bands 2 to 9, and 

 describes the spectrum as superb. Band 3, near D, is of extra- 

 ordinary width. The spectra of this type have been explained 

 as mixed metallic fluting absorption and carbon fluting radiation. 

 The carbon flutings probably present are 5 1 7 and 468-474, which 

 again may be determined by comparison with the spirit-lamp, 

 517 being the brightest green fluting. 



Duner's notation and mean wave-lengths of the dark bands 

 are as follows :— (i) 648-666, (2) 616-2-629 "8, (3) 5^6 7-596-8, 

 (4) 559-8-564 -9. (5)545"2-55i'5. (6) 524-3-528t, (7) 5i6-8- 

 522-2, (8)495-9-503-0, (9) 476-0-483-0, (10) 460-7-473. The 

 bright spaces between 7 and 8, and 9 and 10 are probably due 

 to carbon. 



(4) This is a star of Class II. a, which is now divided into two 

 groups, one having spectra of the type of a Tauri (Group HI.), 

 and the other of the sun (Group V.). The lines should be care- 

 fully observed, and differences from the solar spectrum, if any, 

 noted, so that the star can be classed in one group or the other. 

 The principal criteria so far determined for Group HI. are 

 strong lines at 4C9 and 540, 568 and 579. The line at 540 

 forms with E (5268), and the iron line at 5327 (both solar lines), 

 an equi- distant trio. The difference between the two groups 

 may perhaps best be observed by a comparison of Aldebaran 

 and Capella. 



(5) The spectrum of this star is Class \.a (Group IV.). The 

 relative intensities of the hydrogen and metallic lines should be 

 noted, in order that the star may be arranged with others in 

 order of temperature. 



(6) Duner gives the spectrum of this star as Class \\\.b (Group 

 VI.), in which the main features are three dark carbon flutings 

 fading away towards the blue. Other absorptions, if any, should 

 be carefully observed, and their relative intensities recorded. 



(7) This is a variable star, which reached its maximum on 

 November 6. The magnitude at maximum is given by Gore as 

 6-9-8 '3, and the period as 165-1 days. The spectrum has not 

 yet, so far as I know, been recorded. A. Fowler. 



GEOGRAPHICAL NOTES. 



The telegrams in the papers of Monday and Tuesday from 

 Mr. Stanley are of the most suggestive and interesting character. 

 For one thing, Emin, Casati, and others who have been holding 

 out, are safe, though the brave Pasha has evidently been deserted 

 by most of his men. That Mr. Stanley's expedition was needed 

 the result has proved. He reached the Albert Nyanza for the 

 third time, not a moment too soon to rescue the retreating 

 party. We need not dwell on the sacrifices that have been en- 

 tailed ; they might to some extent have been avoided, but per- 

 sonally Mr. Stanley is not to blame. The geographical results 

 of the expedition, as shadowed in the too brief telegram in 

 Tuesday's papers, are evidently of the highest interest. There 

 is now no doubt that there is a southern Albert Lake, Muta 

 Nzige, which Mr. Stanley has named Lake Albert Edward. 

 From the time when he himself discovered what he called Beatrice 

 Gulf until the present, no one had seen this lake. At first it 

 was thought to be a part of the northern lake, Albert Nyanza, but 

 that idea had to be given up. Now it is clear that it is connected 

 with that lake by the River Sempliki. The southern lake is 

 900 feel higher than the northern, and so is about 3200 feet 

 above sea-level, and 450 feet above Lake Tanganyika, with 

 which it is unlikely to have any connection. Mr. Stanley skirted 

 the snowy mountain range referred to in his letters of six months 

 ago, and found that they send down fifty streams to feed the 



' Roy. Soc. Proc, vol. xlv. pp. 380-392. 



