Transactions of section a. 645 



'The tinle-vate of dilation being _ -— , wbere n is the volume of a given mass, 



may be expressed as ^, where p is the density and the diflferentiation operates 



p ut 

 along the path of the air mass considered. 



To apply this method one must have at his disposal the history of the air- 

 density along the trajectory. Hence one is led to make use of the material 

 discussed by Dr. W. IS^ Shaw, F.R.S., and Mr. R. G. K. Lempfert.i 



An advantage of tbe method indicated is that it permits of an estimate of the 

 upward velocity of the air, at least near the surface. The hydro-dynamical equation 

 of continuity may be written in the form 



dp dp dp dp (du do dtv\ 



or 



1 Dp du dv dw 



-pm-" d^-" d^^ dz " "^ 



where D/D« has the same signification as above. Of the quantities involved in 

 tbe last equation 



_ —^ may be found numerically at any locality, as above ; 



J5-- may be computed by constructing a synoptic chart of the eastward 

 component velocity ; and 



^ may similarly be computed from a chart of the northward velocity ; so 



that the fourth term may be found numerically. 



A theoretical example for the particular case of uniform velocity and constant 

 incurvature of the wind round circular isobars is given. If the dilation vanishes 

 over the surface, the value of the upward velocity for small heights above the 



ground is 



Vza- 

 7V = — bm o 



where V is the velocity of the wind, z is the altitude, a the angle between the 

 wind and the isobars, and r is the distance from the storm centre. 



2. The Meteorology of the "Winter Quarters of the ^Discovery,' 1902-1904. 



By Dr. W. N. Shaw, F.R.S. 



The author gave an account of the meteorological results obtained from the 

 discussion of the observations at the winter quarters of the ' Discovery ' in 

 latitude 77° 50' 50" S., longitude 166° 44' 45" E., for the period February 9, 

 1902, to February 15, 1904, and on the sledge journeys of the Expedition, as 

 published by the Royal Society in 1908. 



3. Results of some Physical Observations taken on the National Antarctic 

 Exjiedition, 1902-1904. By L. C. Beenaochi. 



Tbe 'winter quarters' of the ship ' Discovei^ ' were situated in lat. 77° 50' 45" S., 

 long. 10f;°44' 30" E. 



' The examples shown were taken from The Life History of Surface Air Currentt, 

 by W. N. Shaw, F.E.S., and R. G. K. Lempfert. Meteorological Office Publication, 

 No. 174. 



