32 



NATURE 



[Nov. 13, 1879 



on either side and the front ones are double the size 

 of the others. The genus Dawsonia, allied more or less 

 to Hylonomus, Dawson, is also one of those broad frog- 

 headed salamandroid-looking branchiate amphibia. The 

 sculpturing of the head plates is remarkable, and there 

 appears to be a new bone interpolated behind the post- 

 frontal. Beneath, the vomers have teeth, and so have 

 the long part of the pre-sphenoid, the outer portions of 

 the pterygoids, the palatines, superior-maxillaries, and the 

 pre-maxillaries. The clearly written book is made all the 

 more valuable by the introduction of Miall's reports to 

 the British Association on the labyrinthodonts, and it is 

 pleasing to note the author's graceful recognition of the 

 assistance, he has had in his work from British palaeon- 

 tologists. P. M. D. 



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 of, rejected manuscripts. No 

 notice is taken of anonymous communications. 



[ The Editor urgently requests correspondents to keep their letters as 

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

 is impossible othertvise to ensure the appearance even of com- 

 munications containing interesting and novel facts.} 



An Account of some Marine Animals met with en route 

 to the Cape September 21, 22 



I AM commanded by my Lords Commissioners of the 

 Admiralty, to transmit herewith a copy of a letter from the 

 commanding officer of IT. M.S. Crocodile, giving an account of 

 some marine animals met with en route to the Cape, which may 

 be of some interest to the readers of Nature. 



Admiralty, November 10 Robert Hall 



H.M.S. Crocodile, Simon's Bay 

 September 30, 1879 

 Sir, — I think the following statement may be of some 

 scientific interest, and have the honour to request that it may 

 be attached to my letter of proceedings of this day's date. 



Between the Lat. of j 5„ 53' I s ., and Long, j 5° 44' J g., 



and between the hours of moon setting and daylight on the 

 nights of September 21 and 22, the condensers were continually 

 heating, and the vacuum gauge suddenly dropping to zero. 



On examination of strainers, it appeared that the inlet to the 

 sea-water was choked with a marine animal to an extent that 

 necessitated stopping and clearing four times on the night of the 

 21st Inst., and live times on the night of the 22nd inst. 



On referring to Dallas's "Natural History," the description 

 given of the Pyrosoma, class Tunicata, order A-cidia, corre- 

 sponded in all apparent particulars to the specimens 1 fished up 

 from alongside and took from off the strainers. Those on the 

 strainers were, of course, much flattened by the pressure, and 

 those that had passed through were much attenuated. 



The luminosity of the creatures was very great, and of a most 

 brilliant sapphire colour. I have, &c, 



(Signed) F. Proby Doughty, 



Captain 



To Commodore Richards, A.D.C., Cape of Good Hope 



Easter Island 



As the reviewer of Australasia in NATURE, vol. xx. p. 598, 

 I must ask space for a few further words with regard to Rapanui. 

 Mr. Albert J. Mott draws conclusions with regard to the ancient 

 navigation of the Pacific Ocean and a former condition of high 

 civilisation of the erectors of the stone images, which will not 

 be admitted by any scientific ethnologist. The difficulties 

 attending the erection by savages, or very slightly civilised 

 people all over the world, of large stones has been greatly over- 

 rated. In the case of the stone images of Easter Island, the 

 latest observer, M. A. Pinart, who has paid great attention to 

 this very question and published the fullest account of the 

 matter, together with a series of excellent illustrations, finds no 

 difficulty in accounting for their erection. He writes as fol- 

 lows: — " L'ensemble de ce vaste atelier de statues gigantesques 

 les unes entierement terminees les autres a l'etat d'ebauche et 



en voie d'execution nous permet de nous rendre compte de la 

 facon dont le travail etait accompli, et de la maniere dont elles 

 etaient erigees et mise en place apres feur complet achevement. 

 L'execution de ce travail qui de prime abord parait considerable, 

 qui a tout etonne les voyageurs et sugglrt de noinbrcuscs hypotheses, 

 est cependant d'une grande simplicity. " 



M. Pinart then goes on to explain how the sculptures were 

 always cut out on rocks considerably inclined, and slid down 

 hill to the place assigned, where they were tilted by means of an 

 inclined plane of earth and stones built up, into holes dug deep 

 enough to bury all but the head of each statue. I must refer 

 readers wishing for more detailed information to M. Pinart 's 

 paper, "Voyage a 1'Ile de Paques," Le Tour du Monde, iS"S, 

 p. 225, No. 927, for drawing my attention to which I am indebted 

 to the librarian of the Royal Geographical Society, Mr. Rye. 



The population of Easter Island was by some earlier voyagers 

 estimated at as high as 1,500. It may have been greater, and 

 as many as 500 men would certainly not be required for the 

 erection of any of the images. There was undoubtedly a good 

 deal of wood in the island in old times, and thus rollers and 

 levers would be made use r f. The trees of the island have now 

 been exterminated by the inhabitants. Palmer speaks of a 

 peculiar geslure of the modern Rapanui natives which he 

 compares with certain features in the images. It is the opinion of 

 experts that the general appearance of the sculptured faces is 

 decidedly Polynesian, as far as mode of artistic treatment is 

 concerned. Mr. Mott's conclusion that the existence of these 

 images proves that a nation formerly existed which navi- 

 gated ships to Easter Island at regular intervals, and kept 

 the place going as a colony, will be regarded as simply absurd by 

 any one who knows anything of the science of navigation. So 

 small and so isolated an island as Rapanui could only be reached 

 by navigators who had a very advanced knowledge of astronomy 

 and navigation, and were provided with instruments of great 

 precision, and who had determined the position of the island 

 on maps with exact correctness. No Chinese, Japanese, In- 

 dian, or Arab navigators could have hit on the island 

 except by accident. An exact determination of longitude, 

 as well as of latitude is involved in the matter. A mere 

 knowledge of the compass with even as good information 

 concerning its variations as we now* possess would not avail. 

 The island was discovered by Rcggeveen on April 5, 1722; 

 in 1764 Commodore Hymn, with two ships, sought for the 

 island in vain; in 1766 Bougainville, with two French ships 

 of war, sought for it also in vain ; in 1 767 Capt. Cartaret made 

 the same attempt with a similar result. It was only on March 

 II, 1774, that Capt. Cook found the inland again, and Mr. Mott 

 would have us believe that persons who were by the undoubted 

 evidence of their artistic capabilities and method of treatment 

 of the human figure in sculpture, savages, were able to accom- 

 plish, as often as they wished, a feat of navigation which baffled 

 some of the best European navigators of the eighteenth century. 

 Even at the present day so difficult is the determination of 

 longitude to persons not specially trained as expert navigators 

 that the Island of Bermuda, and even the Virgin Islands have 

 been more than once reported as "gone down" by merchant 

 captains who could not find them. 



With regard to Mr. Mott's "gentle protest" against my 

 statement that "the accepted scientific position is that primitive 

 man was savage," no protest, whether gentle or otherwise, will 

 alter the fact that such is the case ; but it is qnite superfluous to 

 enter into a discussion hereon the general theory of evolution, in 

 accordance with which that position is maintained. 



H. N. MOSELEY 



Silurian Fossils in the Curlew Mountains 

 I BEG to state that the paragraph which occurs in Nature, 

 vol. xx. p. 641, that Silurian fossils have been found in beds 

 amongst the Curlew Mountains "supposed to be old red sand- 

 stone," is nol quite correct. It was very well known in this office 

 that the beds containing the fossils were of the Silurian formation — 

 though erroneously included within the boundary line of the old 

 red sandstone in the Muvey Map, sheet 76. Since the map was 

 engraved, the district to the north and ea-t has been surveyed, 

 and a large fault was discovered, ranging in the direction of the 

 spot where the Silur an fossils have been found. The occurrence 

 of this fault explains the presence of the beds with Silurian fossils 

 within the area of the tract coloured as old red sandstone. 

 There is, therefore, nothing in the announcement in your paper 

 of the slightest novelty, and I have only to state that if the writer 



