May 6, 1920] 



NATURE 



293 



almost-atoll would contain one or several nearly sub- 

 merged islands of mountainous or mountain-top form. 



The characteristics of the small islands of hypo- 

 thetical almost-atolls, as thus deduced from several 

 theories of coral reefs, may be confronted with the 

 appropriate facts as represented in five actual almost- 

 atolls : The Hermit Islands, in the Admiralty group 

 north of New Guinea ; Truk or Hogoleu, in the 

 Caroline Islands; Budd Reef, in north-eastern Fiji; 

 the Great*Astrolabe Reef, in south-western Fiji; and 

 Mangareva or the Gambler Islands, south of the 

 Paumotus. The Hermit Islands are enclosed by a 

 reef about 12 miles in diameter; the largest of the 

 islands is 3 miles long and more than 3000 ft. in 

 height. The encircling reef of Truk is about 30 miles 

 in diameter, and encloses some twenty small islands ; 

 the largest measures 6 by 3 miles, and several of the 

 larger ones are from 1000 ft. to 1300 ft. high ; the 

 smaller ones rise from 20 ft. to 300 ft. Budd Reef 

 measures 12 miles in its longest diameter; three small 

 islands, each less than a mile across, rise from 280 ft. 

 to 480 ft. near the lagoon centre ; a small horseshoe 

 crater island, a mile in diameter and 590 ft. high, 

 near the north-eastern angle of the enclosing reef, 

 appears to be of much more recent origin than its 

 neighbours, and does not bear on the problem here 

 considered. The Great Astrolabe Reef makes an oval 

 loop, 6 miles wide by 10 miles long, around a lagoon 

 containing nine smasl islands; it is not properly an 

 almost-atoll reef, for on the south it continues a long 

 distance around the four-mile island of Ono and the 

 thirty-mile island of Kandavu. However, the small 

 islands that its northern loop surrounds are typical 

 residuals ; the largest is scarcely a mile in length, 

 the highest rises 460 ft. ; all are of rounded, mountain- 

 top form, their small spurs being a little cut back by 

 shore-line cliffs, which rise from low-tide rock plat- 

 forms and do not plunge into deep water. Moreover, 

 a triangular space defined by three of the islands, a 

 mile and a half on its open sides, has the same depth 

 of from 17 to 20 fathoms that prevails between the 

 islands and the barrier reef; and this is beyond 

 explanation by the Glacial-control theory. Gambler 

 Reef is from 12 to 15 miles across ; the enclosed 

 islands are eight in number, and the largest of them 

 measures 4 by 2 miles and has a height of 1300 ft. 

 Dana wrote of the larger of these islands : " The 

 very features of the coast — the deep indentations — are 

 sufficient evidence of subsidence to one who has 

 studied the character of the Pacific islands; for these 

 indentations correspond to valleys or gorges formed 

 by denudation during a long period while the island 

 stood above the sea " (" On Coral Reefs and Islands," 

 1853, p. 95). Within the polygon defined by several of 

 these islands two soundings give depths of 38 fathoms, 

 while the lagoon outside the polygon has no depths 

 so great. 



All these almost-atoll islands are of mountainous 

 or mountain-top form ; they appear to be residuals of 

 originally larger islands, much reduced by sub-aerial 

 r-rosion and now isolated by;* submergence. The 

 smaller ones are mere summits, too small to show 

 ombnved vallevs ; the larger ones have somewhat em- 

 bayed shore-lines, which would, according to the best 

 accounts that I can gather, be more stronglv embayed 

 if the deltas that now partlv occupy the bavs were 

 removed. None of the islands are described as 

 stronglv clift, like those of the extra-tropical seas, 

 although some headlands are a little cut back In 

 low bluffs fronted bv low-tide rock platforms, evt- 

 dently the work of the Ingoon waves at present sea- 

 level. It thus appears that the small islands of actual 

 almost-atolls are excellent counterparts of the moun- 

 tainous or mountain-top islands of hypothetical almost- 



NO. 2636, VOL. 105] 



atolls deduced as the necessary consequences of 

 Darwin's theory, but such islands cannot be accounted 

 for by either Murray's or Daly's theory. 



The attention of European men of science has been 

 so largely withdrawn from the study of coral reefs 

 during the last thirty years that the coral-reef problem 

 now has scarcely a hearing among them. It is to be 

 hoped that, with the acquisition of the numerous 

 islands and reefs of northern and eastern New Guinea 

 with the neighbouring reef-encircled islands by Aus- 

 tralia, the old problem may be taken up again by the 

 explorers and investigators of that remarkable region. 

 The Louisiade group in particular deserves attention. 

 The present communication suggests some of the 

 newer aspects of coral-reef study, which, along with 

 the embayments of reef-encircled islands and the uncon- 

 formable contacts of fringing and elevated reefs with 

 their foundations (see "The Geological Aspects of 

 the Coral-reef Problem," Science Progress, xiii., 

 1919, pp. 420-44), must be taken into account for the 

 future. All considered together, these newer aspects 

 go far towards restoring confidence in Darwin's 

 theory, which between 1880 and 1910 was so un- 

 reasonably discarded by many writers. The theory 

 needs subordinate modification by the addition of 

 changes of ocean-level during the Glacial period, to 

 which Daly has so justly directed attention ; but those 

 changes acting alone would, whenever they occurred, 

 produce emergences or submergences everywhere alike 

 in their moderate amount, their slow rate, and their 

 Pleistocene date; while all the reef-encircled islands 

 that have yet been studied — as, for example, in 

 Foye's "Geological Observations in Fiji" (Proc. 

 Arner. .-Vcad. of Arts and Sci., liv., 1918, pp. 1-145)— 

 testify to submergences and emergences at dates that 

 are frequently unlike from place to place, and of 

 amounts that are frequently much in excess of the 

 most liberal estimates of Glacial changes in ocean- 

 level. Such submergences and emergences are, there- 

 fore, to be explained by local movements of subsidence 

 or upheaval in the islands concerned. As reef-growth 

 has been associated chiefly with the various move- 

 ments of subsidence, reinforced recently by rise of 

 ocean-level, Darwin's theory subordinately modified 

 is thereby supported. W. M. Davis. 



Harvard University, Cambridge, Mass., 

 March. 



Scientific Apparatus from Abroad. 



There is one aspect of the proposed " anti-dumping " 

 legislation to which I should like to direct attention. 



While there is much scientific apparatus made in 

 the British Isles of a quality at least as good as that 

 imported, it is, unfortunately, very costly. But there 

 are also many articles which our manufacturers have 

 not yet learned to produce in anything like a satisfac- 

 tory quality. The result of restricting the import of 

 good articles by a heavy duty would be to compel 

 scientific workers to use home-made goods. There 

 would be no hardship if these goods were satisfactory. 

 But such is by no means always the case, and we are 

 then penalised by waste of time and frequent loss of 

 experimental results. Moreover, if inferior goods 

 obtain a sale by methods of this kind, no inducement 

 is given to the makers to improve the quality. 



I am aware that I may be called a doctrinaire Free 

 Trader, but it seems to me to be a far more reason- 

 able procedure to allow free import of such apparatus 

 until equally good material is to be had cheaply at 

 home. In the meantime, our manufacturers should. 



