728 REPORT— 1881, 



Central Asia, which had been sealed books since the days of Marco Polo, has been 

 explored in many quarters. The elevations of the highest mountains of both hemi- 

 spheres have been accurately determined, and themselves ascended to heights never 

 before attained; and the upper regions of the air have been ballooned to the extreme 

 limit beyond which the life-sustaining organs of the human frame can no longer 

 perform their functions. In hydrography the depths of the great oceans have 

 been sounded, their shores mapped, and their physical and natural history explored 

 from the Equator to beyond both polar circles. In the Arctic regions the highest 

 hitherto attained latitudes have been reached ; Greenland has been proved to be an 

 island ; and an archipelngo has been discovered nearer to the Pole than any other 

 land. In the Antarctic regions a new continent has been added to our maps, crowned 

 with one of the loftiest known active volcanoes, and the Antarctic ocean has been 

 twice traversed to the 79th parallel. Nor have some of the negative results of 

 modern exploration been less important, for the Mountains of the Moon and many 

 lesser chains have been expunged from our maps, and there are no longer believers 

 in the inland sea of Australia or in the open ocean of the Arctic pole. Of these and 

 many others of the geographical discoveries of the last half-century full accounts 

 will be laid before you, prepared for this Section by able geographers; of whom Mr. 

 Markham will contribute Arctic discovery; Sir Richard Temple, Asiatic; Lieut.-Col. 

 Sir James Grant and Mr. H. Waller, African ; Mr. Moseley, Australian ; Mr. 

 Trelawny Saunders, Syrian (including the Holy Land) ; the Ilydrographer of 

 the Admiralty will undertake the great oceans, and Mr. F. Galton will discuss the 

 improvements effectt'd in the instruments, appliances, and methods of investigation 

 employed in geographical researches. 



Of other branches of science which are auxiliary to scientific geography, the 

 majority will be treated of in the Sections of the Association to which they 

 belong; but there are a few which I must not, in justice to the geographers who 

 have so largely contributed to their advance, leave unnoticed. 



Such is terrestrial magnetism ' which had as its first investigators two of our 

 earliest voj-^agers, the ill-fated Hudson and Halley, who determined the magnetic 

 dip in the North polar and tropical regions respectively. Theirs were the precur- 

 sors of a long series of scientific expeditions, duriuff which the dipping needle was 

 carried almost from Pole to Pole, and which culminated in the establishment, 

 mainly under the auspices of this Association, of the magnetic survey of Great 

 Britain, of fixed magnetic observatories in all quarters of the globe, and of the An- 

 tarctic expedition of Sir James Eoss, who, since the foundation of the Association, 

 planted the dipping needle over the northern Magnetic Pole, and carried it within 

 200 miles of the southern one. 



Nor is the geography of this half-century less indebted to physicists, geolo- 

 gists, and naturalists. It is to a most learned traveller and naturalist, Von Baer, 

 that the conception is due that the westward deflection of all the South Russian 

 rivers is caused by the revolution of the globe on its axis." It was a geologist, 

 Ramsay, who explained the formation of so many lake-beds in mountain regions- 

 by the gouging action of glaciers. It was a physicist and mountaineer, Tyndall, 

 who discovered those properties of ice upon which the formation and movement of 

 glaciers depend. The greatest of naturalist-voyagers, Darwin, within the same 

 half-century has produced the true theory of coral reefs and atolls, showed the 

 relations between volcanic islands and the rising and sinking of the bottom of the 

 ocean, and proved that along a coast-line of 2,480 miles the southern part of the 

 continent of South America has been gradually elevated from the sea-level to 600 

 feet above it. Within almost the same period Poulett Scrope and Lyell have 

 revolutionised the theory of the formation of volcanic mountains, showing that these 

 are not the long-taught upheavals of tlie crust of the earth, but are heaped up 

 deposits from volcacic vents, and they have largely contributed to the abandon- 



' The subject of an able lecture 'On the Magnetism of the Earth,' delivered 

 before the Koyal Geographical Society by the Hydrographer of the Admiralty 

 (^Proceedings, vol. xxi. p. 20, 1876). 



" Von Baer, ' Ueber ein allgemeines Gesetz in der Gestaltung der Flussbetten^ 

 St, Petcrsl. Bull. Sc. ii. (1860). 



