104 MR ROBERT C. MOSSMAN ON THE METEOROLOGY OF 



approximation towards the general principles of the atmospheric circulation is to be 

 obtained. 



The region chosen is not only the best but the sole available area in the whole 

 circumference of the globe south of 50° S. which offers a sufficient number of observing 

 stations to warrant serious discussion. 



Maps are given (see Plates I. to IV.) showing the mean monthly and annual dis- 

 tribution of pressure, temperature, and cloud. In their preparation I have drawn lines 

 only for the regions furnishing sufficient data. I have also, as far as possible, en- 

 deavoured to eliminate discordances due to the exceptional characteristics of individual 

 months. With regard to Nordenskjold's observations at Snow Hill and Paulet Island 

 in 1903, and those taken by Charcot at Wandel Island in 1904, I have been able to 

 bring to bear on their discussion the experience derived from a residence during these 

 years at the South Orkneys, which are, from a meteorological point of view, in the same 

 region. In other words, I have tried to represent the conditions at these places as if 

 they had been based on the same five years as were the South Orkney observations. 

 In this connection ordinary methods of differentiation were not of much use, especially 

 with regard to Charcot's 1904 observations, as this was a very exceptional year. It is 

 for this reason that the Isotherms, Isonephs, and the Isobars do not always exactly 

 correspond with the values given in the tables. Even with regard to the South 

 Orkneys and South Georgia, I have allowed myself a little latitude in this direction. 

 For the region of the " Belgica's " drift I have taken the mean monthly temperatures, 

 calculated by Hann,* except that I am inclined to assign to February a lower mean 

 temperature than that given by him. With reference to the observations taken at the 

 Chilian coast stations from 1899-1905,+ the investigation is restricted, except as 

 regards one or two elements such as rainfall, to the five years 1901-1905. The mean 

 monthly temperature, pressure, humidity, and rainfall were for this series extracted 

 from the general summary given in each volume. The mean cloud, wind force, and 

 direction were computed from the tri-daily observations given " in extenso." Owing to 

 the labour attached to work of this nature, an analysis of the winds was made only for 

 Dungeness and Evangelists Island. For New Year's Island the data contained in the 

 MS. sheets of observations were similarly computed from seven daily observations. 

 As regards the Argentine Republic, much valuable information has been obtained from 

 Mr Davis' work on the " Climate of the Argentine Republic," as well as from the 

 elaborate data contained in the " Annals " of the Argentine Meteorological Office. In 

 this connection I have to express my cordial thanks to Mr Davis for permission to 

 utilise the South Orkney and South Georgia observations in so far as they bear on the 

 subject under discussion. I am also indebted to Dr W. S. Bruce for the loan of his 

 valuable meteorological log kept on board the "Balsena" during his voyage to the 

 South Shetlands and Louis Philippe Land in the summer of 1892-1893. 



* Antarctic Manual, p. 44. 



t Annuario del Servicio Meteorologico de la Direccion del Territorio Maritimo, Valparaiso, 1902-1906. 



