July 3i, 1884] 



NA TURE 



3i7 



mens of Mr. Wilson Saunders's Refugium Botanicum, 

 the Madagascar collection of the Rev. R. Baron — this 

 latter of over n 00 species. 



Reference is also made to the " North Gallery," an 

 illustration of which is added to the Report. The collec- 

 tion of separate pictures of plants in the gallery amounts 

 in number to 627, and has since been added to. 



It will be seen from this brief sketch of Sir Joseph 

 Hooker's Report that the work done at Kew is as varied 

 as it is important, and that our colonies directly and our 

 mother country indirectly are under lasting obligations to 

 the zeal and energy of all concerned in the management 

 of this great institution. 



MR. 



THORODDSEN'S GEOLOGICAL 

 EXP LOR A TIONS 



A LTHOUGH situated at a comparatively short dis- 

 ■**■ tance from Europe, and notwithstanding the frequent 

 visits of late years by English tourists, Iceland is yet very 

 far from being a well-known country. The upland is 

 still, for the most part, an unexplored region, and there 

 are whole districts where no man, native or foreign, ever 

 set his foot, owing, chiefly, to the difficulties and dan- 

 gers which attend travelling through these wildernesses. 

 Foreigners travel mostly along beaten tracks ; they come 

 mostly without having acquired any previous knowledge 

 of the peculiar nature of the country, consequently not 

 knowing what parts are most worth visiting or exploring. 

 Yet these regions are eminently interesting for students 

 of natural science, being filled with innumerable glaciers, 

 some of enormous magnitude, with multitudes of vol- 

 canoes, eruptive springs, &c, which it is of the greatest 

 importance should be scientifically explored and described. 

 In order to obtain reliable information about these up- 

 land wilds of the country, the Government of Iceland 

 have commissioned Mr. Th. Thoroddsen to undertake 

 systematic explorations with a view to establishing the 

 geology of the country on a sound basis, and correcting its 

 geography where necessary ; for this purpose he has already 

 undertaken various expeditions. In the course of last 

 summer (1S83) he explored the peninsula of Reykjanes and 

 its upland connections. Although this part lies in close 

 proximity to the inhabited parts of the country, it has 

 hitherto remained for the most part a terra incognita on 

 account of the innumerable waterless and utterly barren 

 lavas which are crowded into it, and make travelling 

 excessively arduous. Formerly people only knew that 

 within historic times two volcanoes had been active in 

 these parts. Mr. Thoroddsen has now determined the 

 existence and site of no less than thirty separate volcanoes 

 with at least seven hundred craters. In each case he has 

 made all necessary measurements, and has constructed a 

 geological map of the whole district. 1 The aggregate 

 extent of the lavas covers about 44 square (geographical) 

 miles. Out of the lavas up and down this tract there rise 

 mountains composed of tufa and breccia, and through 

 these the eruptions of the volcanoes proper have found 

 their vent. Cases of individual volcanoes being built up 

 in one spot by repeated eruptions are rare. The craters 

 are in most cases traceable in distinct long rows, like 

 pearls on a string, along terraces of tufa, situated along 

 chasms through which the lava welled out. In some 

 places there are no craters, the lava having boiled out of 

 the chasm over either side of it, in which cases the rift 

 remains open with its brims covered with a glazed crust 

 of lava. In other localities are found volcanoes of colossal 

 size, broad sublevations or convexities of lava, with a 

 large crater at the apex from Soo to 1000 feet in diameter, 

 instances of which are Skjaldbreid, 3400 feet, and Heidin- 

 Ha, 2000 feet above the level of the sea. Throughout 

 the lava stretches one comes upon enormous fissures all 

 following the same direction as the rows of the craters, 



published by the Geological Association of Stockholm. 



namely, south-west to north-east. All about this district 

 there are also found numbers of hot springs, solfataras, 

 and boiling clay-pits. This peninsula, Mr. Thoroddsen 

 maintains, must be one of the most thoroughly burnt 

 spots on the globe, and a pre eminently instructive tract 

 for geologists who make volcanic manifestations the 

 speciality of their study. 



This summer Mr. Thoroddsen is engaged in exploring 

 the enormous lava wilderness of Odadahraun, covering 

 the central part of Iceland, and, as yet, for the most part 

 entirely unknown. In the glaciers to the south of this 

 wilderness great eruptions have taken place of late years, 

 about which nothing is known, no one having as yet 

 ventured into these wilds, lying 3000 to 4000 feet above 

 the level of the sea. The difficulties of exploration here 

 are enormously aggravated by the utter barrenness of the 

 region, by scarcity of water, and by the frequent snow 

 tempests by which the region is constantly harried even 

 in the midst of summer. Even the compass is not to be 

 relied upon, on account of the mass of iron which enters 

 to such a large extent into the composition of the lava. 



Akreyri, June 24, 1884 



Grimsey is the name of a small island, situated in the 

 Arctic Ocean, about 22 English miles due north of the 

 promontory which divides the bays of Eyjafjord and 

 Skagafjord in Northern Iceland. It is inhabited by 

 SS human beings, debarred from all communication with 

 the outer world, and equally ignorant of its motive thought 

 as of its stirring events. Their intercourse with outward 

 surroundings is confined to Arctic ice and ceaselessly 

 recurring storms. Only once or twice a year they manage 

 in their small open boats, at a perilous risk, to effect a 

 landing on the mainland, for the purpose of obtaining by 

 barter their necessaries of life at some of the north coast 

 trading stations. 



The island having never before been visited by a 

 naturalist, I eagerly embraced the opportunity of joining 

 the governor of the North District on an expedition to it, 

 undertaken at the instance of the commander of the gun- 

 boat Diana, Capt. O. Irminger, of the Danish navy. In 

 the evening of June 19 we steamed, in calm weather, from 

 Akreyri down the broad bay of Eyjafjord, enjoying the 

 imposing scenery of the mountains on either side, lit up 

 by the subdued vermilion tints of the nocturnal sun glare ; 

 when we reached the mouth of the bay, we had a full, un- 

 intercepted view of the midnight sun, resting on the 

 oceanic sky-line, like a ball of fire behind a veil of blood. 

 Out of the inert calm of the deep, which looked like 

 polished glass, there rose on either side of us black pre- 

 cipitous rocks that formed, as it were, the advanced basis 

 of the snow-capped mountain-tops, which determined our 

 sky-line in the landward distance. 



We reached Grimsey at three o'clock in the morning of 

 the 20th, still, as good luck would have it, favoured by the 

 same calm weather and quiet sea — both being the indis- 

 pensable condition of effecting a safe landing on the 

 island. We took the shore just below the parsonage in 

 a bight formed of precipitous rocks made of basaltic 

 columns, here and there split up by yawning caves ; and 

 having succeeded in clambering to the top of the rocks, 

 we set about exploring the island. 



The formation of Grimsey is basaltic throughout, and, 

 geologically speaking, resembles, closely on the whole, 

 the stratification of Northern Iceland. From its non- 

 volcanic nature one may therefore fairly assume that, 

 once upon a time, it must have been connected with the 

 mainland. But, though not volcanic itself, it seems that 

 Grimsey is not very far removed from the lines along 

 which the active subterranean fires in Iceland are 

 operating. At various times the inhabitants state they 

 have observed towards the south-east signs of sub- 

 marine volcanic action, and towards Tjornes (S.S.E.) a 

 column of fire was distinctly observed breaking through 



