Tlie Scientific Advantages of an Antarctic Expedition. 427 



tudes they distribute over the floor of tlie ocean a large quantity of 

 glaciated rock fragments and land detritus. These materials were 

 dredged up by the " Challenger" in considerable quantity, and they 

 show that the rocks over which the Antarctic land-ice moved 

 were gneisses, granites, mica-schists, quartziferous diorites, grained 

 quartzites, sandstones, limestones, and shales. These lithological 

 ^ypes are distinctively indicative of continental land, and there can be 

 no doubt about their having been transported from land situated 

 towards the South Pole. D'Urville describes rocky islets off 

 Adelie Land composed of granite and gneiss. Wilkes found on an 

 iceberg, near the same place, boulders of red sandstone and basalt. 

 Borchgrevink and Bull have brought back fragments of mica-schists 

 and other continental rocks from Cape Adare. Dr. Donald brought 

 back from Joinville Island a piece of red jasper or chert containing 

 Radiolaria and Sponge spicules. Captain Larsen brought from 

 Seymour Island pieces of fossil coniferous wood, and also fossil 

 shells of Cucidlcea, Gytherea, Cyprina, Teredo, and Natica, having a 

 close resemblance to species known to occur in lower Tertiary beds 

 in Britain and Patagonia. These fossil remains indicate in these areas 

 a much warmer climate in past times. We are thus in possession of 

 abundant indications that there is a wide extent of continental land 

 within the ice-bound regions of the southern hemisphere. 



It is not likely that any living land-fauna will be discovered on 

 the Antarctic continent away from the penguin rookeries. Still, 

 an Antarctic expedition will certainly throw much light on many 

 geological problems. Fossil finds in high latitudes are always of 

 special importance. The pieces of fossil wood from Seymour Island 

 can hardly be the only relics of plant life that are likely to be met 

 with in Tertiary and even older systems within the Antarctic. Ter- 

 tiary, Mesozoic, and Palaeozoic forms are tolerably well developed in 

 the Arctic regions, and the occurrence of like forms in the Antarctic 

 regions might be expected to suggest much as to former geographi- 

 cal changes, such as the extension of Antarctica towards the north, 

 and its connexion with, or isolation from, the northern continents, 

 and. also as to former climatic changes, such as the presence in 

 pre-Tertiary times of a uniform temperature in the waters of the 

 ocean all over the surface of the globe. 



Magnetic and Pendulum Observations, Geodetic Measurements, Tides, 



and Currents. 



In any Antarctic expedition magnetic observations would, of 

 course, form an essential part of the work to be undertaken, and the 

 importance of such observations has been frequently dwelt npon by 

 eminent physicists and navigators. Should a party of competent 



