324 INDEX. 



National Physical Laboratory, iii. 



Northerly winds : frequency of, 107, 113 ; mean velocity of, 113 ; temperature during, 46 ; total 

 motion of, 113 ; weather associated with, 11. 



One Ton Camp : position of, 7. 

 Optics, meteorological, v. 



P 



Pack ice, 2. 



Plateau : geogi'aphical features of, 1 ; visits to, 1, 141, 142. 



Potential gradient : annual variation of, 312 ; daily variation of, 314 ; during drift, .306 ; mag- 

 netic declination and, 320 ; instruments and methods, .302 ; negative, .307. 



Precipitation : at Cape Evans, 1.59 ; origin of, within Polar anticyclone, 266. 



Pressure : instrunjents and methods, 163 ; large change from October to November, 186 ; large 

 changes in Iceland, 186 ; non-periodic changes, 184 ; rise due to cyclones near Cape Adare, 

 241. 



Pressure, annual variation : at Cape Adare, 173 ; at Framheim, 171 : at McMurdo Sound, 

 160 ; at Gauss Station and Snow Hill from correlation, 199 ; summary, 17.5. 



Pressure changes and winds, 236. 



Pressure correlation : between the Antarctic and surrounding places, 201 ; within the Antarctic, 

 196. 



Pressure, daily variation : 176 ; abnormal values near 4 a.m., 181 ; at Antarctic stations, 

 182 ; cause of twelve-hourly oscillation, 181 ; Fourier coefficients, 170 ; twelve-hourly period, 

 180 ; twentyfour-hourly period, 180. 



Pressure difference(s) : between Cape Evans and Framheim and winds, 236 ; betweer January 

 and July over the Antarctic, 298. 



Pressure distribution in Ross Sea area : actual, 175 ; theoretical, 219 ; temperature and, 173, 

 237 ; weather and, 238. 



Pressure distribution over the Antarctic : at sea-level, 261 ; at 3,000 metres, 262 ; vertical, 

 258. 



Pressure gradient : in lower and upper atmosphere, 136. 



Pressure, mean monthly : at Cape Adare, 173 ; at Framheim, 171 ; in McMurdo Sound, 167. 



Pressure surges : 189 ; annual variation of, 191 ; affect the whole Antarctic, 193 ; cause of, 

 196 ; centre of system of, 196 ; comparison in Ro.ss Sea area, 191. 



Pressure, winds and weather : chapter VI, 206 ; at Cape Adare, 239 ; at the Gauss Station, 

 241 ; in Ross Sea area, 210. 



PRESSUR.E WAVES : 186 ; comparison at Antarctic stations, 188 ; direction of motion in Ross Sea 

 area, 216 ; effect of, comparison of theory with observations, 230 ; at the Gauss Station, 244 ; 

 moving pressure systems and, 212 ; not caused by blizzards, 235 ; on the plateau, 213 ; theore- 

 tical effect of, 218 ; over the Southern Ocean, 245 ; pressure distribution and, 210 ; winds 

 and, 217. 



Priestly, R. E. : meteorological record at Cape Adare, 10 ; winds at Cape Adare, 128. 



B 



Radiation and cloud, 154. 



Radio-activity : atmospheric, 320. 



Range, daily : definition of, 53. 



Reduced range : definition of, 73 ; correlated to maximum and minimum temperatures, 74. 



Ross, Captain Sir J. C. : discovery of the Ross Sea, 1, 2. 



Ross Sea : geographical features of, 1 . 



RuDGE, W. A. D. : electrification of dust, 309. 



s 



Sastrugi : in McMurdo Sound, 111. 



SciLLY Isles : gustiness at, 118. , 



