i6 



DEPTHS OF THE OCEAN 



The 



•' Valdi/ia/ 



Chun. 



previously indicated. His scientific results were published in 

 the English language in six handsome volumes. 



During 1895 and 1896 the Danish ship " Ingolf " was 

 engaged in the investigation of the northerly portions of the 

 Atlantic, the physical and biological results being published in 

 English. 



From 1897 to 1909 Sir John Murray, associated at first 

 with F, P. Pullar and afterwards with Laurence Pullar, carried 

 out a bathymetrical survey of the Scottish fresh-water lochs, 

 including detailed physical and biological observations, and the 

 report on the scientific results was published in six volumes in 

 1 9 10. During these investigations very careful observations 

 were made by Chrystal on seiches, as a result of which our 

 knowledge of these oscillations and their causes was widely 

 extended. Another kind of oscillation was also discovered, 

 which has been called the temperature seiche. This occurs at 

 the discontinuity layer, where there is a rapid fall of temperature. 

 This temperature oscillation in Loch Ness had a period of 

 about three days, and a maximum rise and fall of about 200 

 feet. The period of these oscillations is dependent on the 

 difference in density between the upper warm layer and the 

 lower cold layer : the smaller the difference in density, i.e. the 

 smaller the temperature differences in a lake, the longer does the 

 period of the oscillation become. These observations in the 

 Scottish lakes have recently been extended by further systematic 

 work in Loch Earn under E. M. Wedderburn, and have already 

 suggested explanations of phenomena in the ocean, where long- 

 period oscillations are observed in various depths, and the 

 explanation is probably the same as that given for the lakes. 



In the years 1897 to 1899 the Belgian Antarctic Expedition 

 on board the " Belgica " carried on important work. This was 

 the first vessel to winter in the Antarctic regions, and the 

 scientific results are necessarily of great interest and value. 



In 1898-99 the German Deep-Sea Expedition on board the 

 " Valdivia" investigated the physical and biological conditions 

 of the Atlantic and Indian Oceans, penetrating into the 

 Antarctic as far as the ice would permit. The extremely 

 valuable scientific results are being issued in a series of 

 magnificent memoirs under the editorship of Chun, the leader 

 of the expedition. 



In 1899 the U.S.S. "Nero" surveyed the route for a 

 telegraph cable between the Sandwich and Philippine Islands 

 by way of Midway and Ladrone Islands, many of the soundings 



