THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 



289 



Diurnal Pkriod. 



The following table shows the mean umouut of cloud at four-hourly intervals for 

 the seasons and the year. 



Hence the maximum occurs at all seasons either at noon or 4 P.M., while the mini- 



mum is recorded at midnight. 



Sdnshine. 



On the visit of the "Scotia" to Port Stanley in January 1903 a Campbell Stokes 

 sunshine recorder was left in charge of the Governor, His Excellency Sir William Grey 

 Wilson, K.C.M.G. The instrument was exposed in a good situation at Government 

 House ; and although hills ranoino; from 800 to 1700 feet to the south and west do not 

 permit of a clear horizon in these directions, yet they are so far away that it is not likely 

 that the amount of sunshine is materially reduced. The following table gives the mean 

 amount of sunshine in hours, along with the percentage of the possible duration ; and 

 the frequency of sunless days, the total possible for each day in the year, being calculated 

 from the data given in Burdwood's Azimuth Tables.* 



* " Sun's True Bearing or Azimuth Tables, computed for intervals of four minutes between the parallels of 

 latitude 30° and 60° inclusive," by John Burdwood, Staff Commander R.N. London, 1894. 



