June 28, 1883] 



NA TURE 



209 



The Great Comet of 1882. — In No. 2521 of the Astrono- 

 mische Nachrichten is an elliptical orbit of this comet by Mr. 

 John Tatlock, jun., of Williamstown, Mass., with a period of 

 1376 years, which, as Prof. Krueger remarks in a note, differs 

 materially from the results of Kreutz, Frisby, and Fabritiis. 

 It may be added that the new calculation can have little weight, 

 being founded upon normals for October S, November 24, and 

 January 29, so that at the date of the first normal the comet was 

 already far past the perihelion, and in fact during the whole 

 interval only described a heliocentric arc of about 5° 10'. Dr. 

 Kreulz has shown the possibility of closely representing by the 

 same orbit the anteperiheli on observations and tho e made sub- 

 sequently to perihelion passage, though there may be need of 

 much more minute discussion before it can be safely assumed 

 that there was absolutely no appreciable effect from the comet's 

 passage through the solar coronal region. 



GEOGRAPHICAL NOTES 



Science announces that Lieut. Schwatka, accr.npanied by 

 As-istant-Surge™ Wilson, C. A. Ilomin, U.S. Engineer Corps, 

 and three private soldiers, left for Chilkat, Alaska, May 22, 

 from Portland, Or., on the steamer Victoria. They are pro- 

 visioned for a six months' cruise, will employ Indians for packers, 

 &c, and intend to ascend the Chilkat River to its head, make 

 the passage to the head waters of the Lewis River, and descend 

 the same to its junction with the Yukon, and descend the Yukon 

 River to its mouth. It is said to be their intention to survey the 

 course of these rivers ; and there i; no doubt that a properly 

 qualified and equipped party would find abundance of useful 

 work ready to their hands. The wh ile route has bee 1 travelled 

 before, but not by persons in search of and qualified to obtain 

 geographical information, except in very small part. The ex- 

 plorations of the Krause brothers on the Chill, at and vicinity 

 have been alluded to before. The Yukon has heen superficially 

 examined by McMurray, Ketchum, Zagoskin, Pall, Whymper, 

 Raymond, Nelson, and others, and a few points have been 

 as ronomically determined ; but nothing like an exact map has 

 been attempted, nor do the data for it exi-t. Astronomical and 

 magnetic observations anywhere along its banks, and especially 

 any data for a map of the Lewis River and its feeders (which are 

 only known from the reports of projectors and natives), would 

 be of the highest interest. 



At last news has again been received by Dr. Schweinfurth 

 from the well-known African explorer, Dr. W. Junker. He 

 was still in the Nyam Nyam country, and his last news was 

 dated October 16, 1SS2, from the residence of a chief named 

 Semio some days' journey south of the Mosio district of the 

 present maps. Dr. Junker, who has travelled through vast .li>- 

 tricts hitherto unexplored, will now soon return home. The last 

 time he had spent principally in various excursions, during which 

 he repeatedly crossed the Utile River to the south, and als ■ the 

 third degree north latitude, leaving his provisions in the care of 1 1 i ^ 

 companion, Herr Bohndorff. On September 27 he again j lined 

 the latter after an absence of eighteen months, but found him so 

 poorly that he had to send him home with the collections made 

 up to that time. Bohndorff started with thirty-two porters, who 

 carried the natural history and ethnographical collections. Of 

 special interest for geographers was an excursi jn nf Dr. Junker's, 

 which he made south of the former Munsa district of the Mon- 

 buttu. Some seven days' journey (about 60 kilometres) south of 

 this place he reached a large river named the Nepoko. which 

 the traveller identified with Stanley's Aruwimi, ore of the main 

 northern tributaries of ihe Congo in the middle course of the 

 latter. 



Dr. Pogge has sent a report from the Mukenge station on 

 the Lulua regarding his return journey from Nyangwe, showing 

 that this was not quite as peaceable as the journey to Nyangwe, 

 and that he had frequently to defend himself seriously against 

 the enmity of the natives. From the Lualaba to the Lomani, 

 Dr. Pogge travelled by the sa lie route as he had previously c rnie 

 with Lieut. Wissmann 



One of the most recent additions to the "Bibliotheque d' A ven- 

 tures et de Voyages" published by Dreyfous of Paris is a volume 

 containing the letters and journals of La Perouse during his 

 famous voyage round the world in 1785-88, which ended in the 

 disappearance of the circumnavigator among the islands of the 

 South Pacific. The volume is annotated by M. George Mantoux, 

 who also supplies a prefatory memoir of the great sailor. 



" Im Reiche des /Eolus" is the title of a little book by Adolf 

 von Pereira, published by Hartleben of Vienna, and containing 

 reminiscences of a tour the author undertook to the Lipari Isles. 

 It is profusely illustrated and contains a map. 



Austrian papers report that a mountain in the neighbourhood 

 of Czernowitz, in the Bukovina, is manifesting singular symptoms 

 of disturbance. The ground around its base, to the extent of 

 over 1000 fathoms, has opened out in wide and deep chasms. 

 Most of the hou es of a village on the spat (Kuczumare) ha\e 

 fallen down. 



The Thuringian Geographical Society met at Jena on the 

 17th inst., when Prof. Hseckel read a paper on the flora of 

 Ceylon, and Herr G. Kurze one on the outposts of European 

 civilisation on the way from Zanzibar to Lake Tanganyika. 



THE SPECTRUM OF THE AURORA 

 TN view of the increased frequency of auroras, an inquiry into 

 •*■ the present position of our knowledge as to theirspectra has 

 seemed to me desirable. 



The accompanying table gives in wave-lengths all the observa- 

 tions I could find of the position of the bright lines of the 

 auroral spectrum. J. R. Capron's " Aurora? and their Spectra," 

 goes more fully into the subject than any other work I know, 

 and therefore many of the positions are taken from it, being 

 found on the 1 age or plate indicated in the column headed 

 " Page, &c." The authorities for other observations are given 

 in the notes, but in other ca^es again I cannot now state whence 

 I obtained them. 



They are arranged approximately in order of accuracy, 1 but 

 this is manifestly a very difficult matter to decide : if, as is very 

 likely, I have made mistakes in this respect, 1 hope I shall be 

 excused. I have gone very carefully into the matter, judging of 

 the accuracy of the observations partly by their internal evidence, 

 and partly by the weights which are in some cases attached to 

 them by the observers themselves. 'Ihe observers' probable 

 errors are given in the table after the positions of the lines. I 

 ons ; der 1. R. Capron has attributed too much accuracy to most 

 of the observations of ihe auroral s. ec rum that have hitherto 

 been mide ; certainly he has to mine. Nearly all the observers 

 have measured the principal line ; and, as ils position i- very 

 well known, the meaurements of it are to a cons derable extent 

 a guile to the amount of dependence that may be placed on the 

 rest. Of co.irse it may happen to he mea-ured correctly by 

 accident, while the rest are incorrect ; but, on the other hand, if 

 it is incorrectly measured, it is not likely that the rest will be 

 correct. It is, therefore, very desirable lhat observers should 

 measure this line at the same time as they measure any of the 

 others ; mt necessarily in order to a certain its position, but as 

 an indication of the correctness of the re-t ; although it does not 

 always happen that all the lines are by any means equally 

 accurate. 



The most probable positions of the lines, given at the foot ot 

 the table, are derived from the most accurate of the observations 

 of each. Below are indicated the observations which have 

 been used in the calculation in each case, with the weight given 

 to each ; for I have not taken the simple average of those used, 

 but have given higher weights to those that seemed the best 

 The " Probable Error," as given below the " Probable Average, 

 is partly calculated and partly estimated ; it seems rather large ; 

 perhaps it should not really be so large. 



My second series of observations (No. 18 in the table) are not 

 absolute measurements, but only comparisons with o and 7. I 

 have therefore not used them in the calculation of the general 

 averages. This series is most likely affected by constant errors 

 much" larger than the probable errors given in the table from 

 calculation. It seems rather curious that the actual errors of my 

 first series (No. 17) are nearly all so much greater than the probable 

 errors ; and possibly the same thing may occur in some other 



cuses 



E. B. Kirk's observation (No. 2S) (though a very rough one 

 as regards position) is one of the mo,t striking of all ; and, bein,' 

 unique, confirmation of it is very de-irable. It will be described 

 under the different line-, &c, concerned. 



Where 1 have attached to an observation a Greek letter wiih 

 a note of interrogation, it means that it is uncertain whether the 



' But the observations of each observer are placed together, however 

 unequal in accuracy they may be. 



