PRESIDENTIAL ADDRESS. 31 



Nearer the main hut was the small magnetic hut for absolute 

 magnetic measurements. Alongside an ice grotto was cut 

 out for the continuous magnetic trace, and it was ingeni- 

 ously connected electrically to the hut, so that any accident 

 to the apparatus was signalled by a bell. A portion of the 

 main hut was devoted to meteorological and physical 

 apparatus. It contained, inter alia, a Dine's pressure- 

 tube anemometer — frequently consulted by the laymen — 

 which registered every gust of wind as well as giving a 

 continuous windgraph. The electrical condition of the air 

 was frequently tested, while a wind direction chart was 

 obtained each week. The outer temperature was recorded 

 on a drum within the hut by means of specially designed 

 apparatus. 



There were in addition, thermographs and barographs of 

 a more ordinary pattern. These continuous records were 

 checked every four hours during the whole stay of the 

 expedition at Cape Evans, by readings of standard instru- 

 ments, and the two sets were found to agree excellently. 



Mr. Nelson carried out experiments on the relation 

 between the temperature of the sea water and the distribu- 

 tion of the plankton. A snow wall was built around a hole 

 in the sea-ice, and this was kept open all winter. He 

 collected specimens of sea water and carried out dredgings 

 here, besides making soundings at regular intervals in the 

 bay (through the ice) to map the extraordinary contours 

 of this portion of MacMurdo Sound. 



A tide gauge gave continuous records, and three distant 

 thermometer screens on the sea-ice, and on the slopes of 

 Erebus were of great value in discussing temperature 

 distribution. 



Of great value to the biologist and to the geologist are 

 Ponting's photographs and cinematographs of the bird and 

 animal life and of the scenery in the vicinity of the hut. 



