Dec. 5, 1889] 



NATURE 



105 



Dictionary," and is assigned to the year 1660 : — "To take the 

 opposite course and to provide our remedy antiparallel to their 

 disease." Here it seems inttnded to convey the idea of "parallel 

 and in the opposite sense." 



In Barlow's " Mathematical Dictionary" (1814), the modern 

 meaning is given, and the old error as to the ratios of the 

 segments of the sides of the triangle is pointed out. 



In Rees's " Cyclopaedia" (1819) the modern meaning is given, 

 but a remark is added that Leibnitz used the word in the sense 

 explained above ; as no reference is given, we cannot tell 

 whether the writer meant that he habitually used it or only in 

 the article on the catenary. E. M. Langley. 



Bedford. 



A Surviving Tasmanian Aborigine. 



In your issue of November 14 (p. 43), you refer to the paper 

 read by Mr. James Barnard before the Royal Society of Tasmania 

 on a Mrs. Fanny Cochrane Smith, who lays claim to be the last 

 surviving aboriginal Tasmanian. Since your note appeared, I 

 have read a report of the paper published in the Hobart Mercury 

 of September 10 last, and think my view on the claim may be 

 of some interest to your readers, 



Mr. Barnard states that he knew Mrs. Smith forty years ago 

 when she was seventeen years of age, and that during the period 

 which elapsed since then until she called upon him shortly before 

 he wrote his paper, he had not known of her whereabouts. In 

 favour of the claim I can only find that she has, with apparently 

 one exception, always been referred to officially as a pure-bred 

 aborigine, and that Parliament appears to have voted her grants 

 on two occasions (in 1882 and in 1884) on account of her unique 

 position. 



The objections to the claim may be briefly summarized as 

 follows : — 



(i) From the meagre account given, it appears her hair and 

 complexion are both that of half-castes, and we are not supplied 

 with any other description of her features or stature or pecu- 

 liarities so as to be able to judge on the question. 



(2) Beyond the mere statement as to mutual recognition no 

 evidence is given that the claimant is the same girl Mr. Barnard 

 knew forty years ago at Oyster Cove, nor, indeed, is there any- 

 thing to show that this woman is the child, or one of the children, 

 referred to by Lieut. Friend in controverting Count Strzelecki's 

 well-known views, which quasi fact forms the foundation for the 

 claim. 



(3) The woman herself is reported to have no recollection of 

 witnessing, at the age of thirteen, a document sufficiently im- 

 portant to have impressed itself on her memory, and it is 

 somewhat strange that this very document is said to describe her 

 as a half-caste. 



It would, no doubt, be interesting were it to be eventually 

 proved that this woman Fanny is a pure-bred aborigine, but for 

 the present Truganina must be considered the last survivor of 

 her race. Hy. Ling Roth. 



Lightcliffe, November 23. 



Brilliant Meteors. 



The brilliant meteor seen at Warwick School and in 

 Cumberland I saw at Folkestone on November 4 a little before 

 8. It was travelling slowly from north-west to north, about 

 30° above, and parallel with, the horizon. After travelling some 

 distance it appeared to partly explode, and then went a little 

 farther and burst. At first it was a beautiful green colour, but 

 after it had partly burst it was nearly white. I imagined its 

 colour was through the haze there was in the sky. From what 

 I saw I am certain it would have been a splendid sight had 

 the atmosphere been clear. P. A. Harris. 



Inchulva, Maidstone, November 27. 



Last night, in clouded moonlight, whilst walking here from 

 Newton by the road over Little Dunnow, my attention was 

 arrested by the glare of what must have been a very bright 

 meteor, seen through clouds which formed a general covering. 

 The quarter in which the light appeared was east by north, at 

 an elevation of about 25°, and it lasted a second and a half. 

 There appeared to be three centres of illumination, but these 

 may have been only thinner portions of the clouds. The time, 

 as nearly as I could get it by comparing my watch by telegraph 

 at the village post office this morning, was 22h. 48m. 45s. 



Slaidburn, Clitheroe, December 2. R. H. Tiddeman. 



REPORT ON THE MAGNETICAL RESULTS OF 

 THE VOYAGE OF H. M.S. ''CHALLENGER." 



IT will be remembered by readers of the " Narrative of 

 the Voyage of H.M.S. Ckallenger," that Vol, II., , 

 published in 1882, contained a report of the magnetic 

 observations made in that vessel in considerable detail. 

 It has, however, been reserved to the present year for a 

 full discussion of the Challenger observations and their 

 bearing on our existing knowledge of terrestrial mag- 

 netism to be made, and the following is an abstract 

 of the final Report about to be published in Vol. II., 

 "Physics and Chemistry of the Voyage of H.M.S, 

 Challenger." 



The method of representing the values of the magnetic 

 elements by curves of equal value has, since 1700, when 

 Halley published his map of the declination, found 

 general favour ; for in succeeding years we find Moun- 

 tain and Dodson, Churchman, Yeates, and Barlow, also 

 published maps of the same magnetic element. 



In 1819, Hansteen added maps of inclination to the 

 declination for certain epochs, and in 1826 produced a 

 chart of isodynamic lines, revised in 1832. 



Following Hansteen, there appeared, in 1840, Gauss 

 and Weber's atlas, the result of calculations from about 

 eighty-four observations distributed over the world, pre- 

 senting a remarkable approach to the truth, even when 

 viewed in the light of our comparatively extended know- 

 ledge of the earth's magnetism in the present day. It 

 may be observed that, if only a fresh magnetic survey of 

 the regions south of 40° S. latitude were now made, a re- 

 calculation of the Gaussian constants might be under- 

 taken promising important results. 



Between 1868 and 1876 Sir E. Sabine's "Contribu- 

 tions to Magnetism" were read before the Royal Society, 

 forming a series of papers on the magnetic survey of 

 the globe for the epoch 1842-5. Although the maps ac- 

 companying these contributions serve as a point of 

 departure for comparison with subsequent maps, an ex- 

 amination of them shows that in Africa and the North and 

 South Pacific Oceans there were large blanks from want 

 of observations 



There remained, therefore, a large field for observation, 

 and it will now be shown how largely the Challenger 

 Expedition contributed to the filling up of these blanks, 

 and added to our knowledge of the changes going on in 

 the magnetic elements in places visited by previous 

 observers. 



The whole of the magnetical fesults have been em- 

 bodied with others from every available source in four 

 charts^ of the magnetic elements, for the epoch 1880, 

 which may prove acceptable to magneticians desirous 

 of noting the changes in the magnetic elements since 

 1842-5. 



The Challenger w^.s not an ideal ship in which to con- 

 duct magnetic observations at sea, for she was seldom at 

 rest from pitching and rolling, and although the errors in 

 the observations caused by the horizontal component of 

 the ship's magnetism were moderate, and could be 

 eliminated by "swinging" the ship, those proceeding 

 from the vertical component were large, and necessitated 

 a frequent comparison with normal values on land. But 

 by discussing fully a series of observations made in 

 numerous places in both hemispheres where no trace of 

 local magnetic disturbance could be found, the magnetic 

 condition of the ship was readily determined for any 

 period of the voyage. As a consequence of this, normal 

 values of the magnetic elements could be obtained in the 

 neighbourhood of places known or suspected of being 

 affected by local magnetic disturbance, and the amount 

 of such disturbance measured with considerable accuracy. 



This method of detecting local magnetic disturbance, 



' Note published with the " Report of the Scientific Results of the Voyage 

 of H.M.S. Challenger," Physics and Chemistry, Vol. II., Part VI. 



