40 



NATURE 



[May 10, 1888 



plates, the bottom member itself being strengthened 

 internally at the junction by suitable diaphragms. 



The importance of this junction will be readily under- 

 stood, when it is stated that a load of some 6000 tons — 

 the weight of an American liner — will be transmitted 

 through it, in the finished structure, on its way to the 

 masonry pier. Some 16,000 rivets are required for the 

 junction ; and large as this number may appear, it bears 

 but a small ratio to the eight million rivets used in 

 the whole structure. The method of construction of the 

 junction was that uniformly adopted in dealing with these 

 members. The junction was erected on the drill roads 

 attached to the workshops at South Queensferry, all 

 holes drilled by specially designed plant ; and, having 

 been marked for re-erection, it was taken down and trans- 

 ported plate by plate, and finally hoisted into position 

 in the finished structure from a steam barge, by a crane 

 working from the internal viaduct. 



The tie was built downwards from the top of the 

 vertical column ; the timber cage — shown in our illustra- 

 tion — in which the men worked being attached to and 

 following it as length by length was added. To design 

 and build a structure of steel to bear a load of some 

 6000 tons is no mean task in itself, but what shall we 

 say of the whole undertaking, when this junction alone 

 contains but one five-hundredth of the material required 

 for the completed Forth Bridge? 



FLORA OF THE ANTARCTIC ISLANDS. 



MR. W. B. HEMSLEY, who elaborated at Kew 

 the collections made during the Challenger 

 expedition illustrative of the floras of oceanic islands, 

 has handed to me the following interesting letter from 

 Dr. Guppy. The materials and notes accumulated by 

 this skilful observer during his travels in the Western 

 Pacific threw a good deal of light on the mode in which 

 oceanic islands were stocked with plants, and Mr. 

 Hemsley was able to make an advantageous use of them 

 in discussing the collections made in the same region by 

 Prof. Moseley. 



I myself am very much impressed with the probable 

 truth of the views expressed by Dr. Guppy. It would 

 be very desirable to obtain additional observations which 

 would serve to test their accuracy. It is with this object 

 that I have obtained Dr. Guppy's permission to com- 

 municate his letter to Nature. 



W. T. Thiselton Dyer. 



Royal Gardens, Kew, April 28. 



17 Woodlane, Falmouth, April %, 1888. 



As I am likely to be proceeding soon to the South Seas, I 

 have been re-perusing your volume of the " Botany of the 

 Challenger" more especially the remarks concerning the dispersal 

 of plants, which I hope to take the opportunity of following up 

 in a more systematic way than before. 



I was thinking that if you thought it worth while you might 

 direct the attention of masters of ships going round the Horn 

 and the Cape of Good Hope to the chance of finding seeds in 

 the crops of the oceanic birds that follow the ships in the 

 regions of the westerly winds. I am inclined to believe that 

 important results would be obtained. Judging from my 

 experience, about one bird in twenty-five would contain a seed in 

 its crop. 



1 am still inclined, if you will pardon my saying so, to the 

 belief that the agency of birds like the Cape pigeons may 

 explain some of the difficulties in the floras of the islands in the 

 Southern Ocean. To return to the instance of my seed, I have 

 since found an account where a Cape pigeon, around the neck 

 of which a ribbon had been tied, followed a ship on its way 

 home from Australia for no less than 5 000 miles (Coppinger's 

 " Cruise of the Alert" 1885, p. 18); and on consulting other 

 voyages I find that the Cape pigeon appears to perform the 

 circuit of the globe in the region of the Westerlies, so that my 

 seed might readily have been transferred from Tristan d'Acunha 

 to Amsterdam. 



A remarkable point has occurred to me whilst reading your 

 remarks (doubtless you have already thought of it). In a 

 botanical sense, and also in a geographical sense, the Antarctic 

 Islands seem to be arranged in two parallel zones. Tristan 

 d'Acunha, Amsterdam, and St. Paul's, lying between the parallels 

 of 37 to 40° S. lat., have similar floras. Further south is the 

 second zone, between 47° and 55 (cirea), in which the land 

 and islands (Fuegia, Crozets, Kerguelen, Macquarie, &c.) are 

 characterized by their common floras. Now, how are these two 

 parallel botanical zones to be explained ? ' It seems to me that 

 if you grant that the northern zone may largely derive its 

 common characters by the agency of birds following the 

 westerly winds, such as I believe to have been the case, you 

 are almost forced to the conclusi >n that the floras of Fuegia, 

 Kerguelen, Macquarie Island, &c, in the southern zone have 

 obtained their common characters, in the same way. Of course 

 the distinctiveness between the floras of the two parallel zones 

 would then be explained by the difference in the climatic con- 

 ditions arising from difference in latitude. For my own part I 

 do not think the hypothesis of a sunken southern tract (or tracts) 

 of land to be supported by geological evidence. Is not the 

 geological character of the remote oceanic islands strongly 

 negative of the idea that they are portions of ancient submerged 

 tracts? Can Kerguelen, Amsterdam, &c, be in any sense 

 continental islands as regards their rocks ? With reference 

 to New Zealand, if geologists are right in regarding it as lying 

 along the same volcanic line that extendi southward through the 

 Western Pacific from New Guinea, then it is probable that the 

 vast post-Tertiary upheaval of the island groups (Solomon Islands, 

 New Hebrides, &c. ) which I have shown to have taken place 

 along this line of volcanic activity in the Western Pacific, has 

 been represented in New Zealand by elevation rather than de- 

 pression. I believe that subsequent investigation will confirm 

 my belief that the great island groups of the Western Pacific, with 

 New Caledonia and New Zealand, have been always insular. 

 This is, I think, the great lesson I learned in the Solomon 

 Islands. H. B. Guppy. 



LORD HARTINGTON ON TECHNICAL 

 EDUCATION. 



THE Marquis of Hartingtcn was the chief guest at the 

 anniversary banquet of the Institution of Mechanical 

 Engineers held on Friday, May 4, at the Criterion 

 Restaurant. Mr. Edward H. Carbutt, President of the 

 Institution, occupied the chair. In responding to the 

 toast of "Our Guest," proposed by the Chairman, Lord 

 Hartington, after speaking of the part which the me- 

 chanical engineering profession of this country takes in 

 the maintenance and the extension of our material and 

 industrial supremacy in the world, referred to the vast 

 importance of technical education. He had never pro- 

 fessed to be an authority on the subject of technical 

 education— he was no authority on that subject ; all he 

 could do in the position he held was to endeavour to 

 arouse such interest as he could in that subject, to enlist 

 in the minds of the ordinary public — the unscientific 

 public of whom he formed a part — an interest in this 

 question, and to listen to the advice and attend to the 

 counsel which were given to the public by those who were 

 authorities on the subject, and to whose advice he held 

 it was most important that attention should be paid. He 

 had been greatly struck by the fact that in every country 

 in Europe which competed with us in industrial or com- 

 mercial pursuits greater attention had recently been paid 

 to giving a practical direction to the national education 

 than had hitherto been considered necessary in England. 

 We had, like other countries— perhaps somewhat in arrear 

 of them — established a national and tolerably complete 

 instruction ; but they, earlier than we, had embraced 

 the idea of making that national instruction not only a 

 literary instruction, but a technical and commercial edu- 

 cation. But he could not help thinking that in that 

 respect they had gained some considerable advantages 

 over ourselves. He did not think there was any occasion 

 for us to take a desponding or a pessimistic view of the 



