122 MR ROBERT C. MOSSMAN ON THE METEOROLOGY OF 



Table XIV. gives the mean force of the different winds for the same region on 

 the Beaufort scale of 0-12. 



With regard to these Tables X. to XIV., in which the data utilised are based on a 

 different number of daily observations, the values of the various expeditions have been 

 weighted so as to allow for this. Thus on the "Challenger" and "Scotia" hourly 

 observations were taken, while in Ross's Expedition and others the available data refer 

 to observations made every four hours, and in some cases at even longer intervals. With 

 regard to Biscoe's observations a numerical value (on the Beaufort scale) has been 

 applied to his descriptive terms, such as "strong breeze," "moderate breeze," "gale," 

 etc.; the directions given when "magnetic" have been referred to the "true" 

 meridian by applying the variation for the epoch and locality of observation. 



Table XV., showing the force of the different winds during the drift of the " Belgica," 

 has been prepared from the observations given in extenso in M. Arctowski's report,* 

 the hours utilised being 4 a.m., 8 a.m., Noon, 4 p.m., 8 p.m., Mdt. 



Table XVI. gives an analysis of gale frequency at Evangelists Island and Dungeness, 

 deduced from a detailed examination of the tri-daily observations published in extenso in 

 the annual volumes of the Maritime Department of the Republic of Chili, 1901-1905. 



Table XVII. gives a condensed abstract of the mean barometric pressure, tempera- 

 ture, etc. of the different winds at Cape Pembroke, Falkland Islands, and at the South 

 Orkneys, for the seven months April to October 1903. 



Table XVI II. contains similar means based on the sixty-four days' observations taken 

 by Dr Bruce in the vicinity of Louis Philippe Land and the South Shetlands from 

 December 1892 to February 1893. 



Table XIX. shows the departure from the mean of average values of pressure, 

 temperature, etc. during the cruises of the "Scotia" in the Weddell Sea during the 

 summers of 1903 and 1904, for each Wind Direction. 



Table XX. gives the barometric and thermal windrose for the seasons and the year 

 during the " Belgica's" drift, and the seasonal and annual departures from the normal. 

 This table is based on those given by M. Arctowski on pages 36 and 38 of his work, 

 but the directions have been reduced to eight points. With reference to these tables 

 of windroses (Tables XVII. to XX.), it may be observed that the values have been 

 reduced to eight directions by halving the intermediate points between the octants. 

 The annual and seasonal means of the climatic elements are not the averages of the 

 monthly values, each of which is derived from a different number of observations, but 

 are the arithmetical means obtained by dividing the gross totals by the number of 

 observations of the wind in question. 



Table XXI. gives the departure from the mean of the temperature of the different 

 winds at Staten Island and Rawson for January, April, July, and October, and the 

 mean of these four months as representing the year. The data are taken from The 

 Climate of the Argentine Republic, by W. 0. Davis, p. 28. 



* Expedition Antarctique Beige : Ke'sultatsdu Voyage du S.Y. " Belgica" : " Met^orologie," par Henryk Arctowski, 

 Anvere, 1904, pp. 58 to 83. 



