90 Transactions of the South African Philosophical Socvety. 
upon the rate of fall of temperature than upon its actual degree. 
The space over which it extends will be much larger and much less 
clearly defined than the corresponding space about H, the wind- 
frequency maxima being less pronounced accordingly. 
It must not be imagined for a moment that Fig. 8 represents the 
path of any particle of air. Such an idea would imply velocities of 
upwards of a thousand miles an hour, which are, fortunately, out of 
the question. We are simply asked to understand that as Kimberley 
describes its diurnal rotation, its mobile air covering takes up succes- 
sively the directions of motion of those portions of the imaginary 
vortex-system through which it may be passing. Hach particle will 
tend to describe a spiral it is true, but in no individual case will the 
actual path accurately resemble that of the diagram, although the 
mean path of all the particles may do so in general shape. — 
It seems to follow that the diurnal wind system of Kimberley must 
be exceedingly shallow, not extending many thousand feet above the 
earth’s surface, and this is supported by the motion of the clouds 
which, with few exceptions, travel along paths radiating from some- 
where between north and west, irrespective of the wind directions 
below. 
If the wind system of Fig. 8 is a correct interpretation of the 
Kimberley winds, it must be of universal application; and should, 
when allowances have been made for latitude (north or south), for 
prevailing winds, land- and sea-breezes, &c., apply to every place 
lying within 45° of the equator, if not beyond. The winds of 
Adelaide certainly seem to come within its scope, and possibly also 
those of Cordoba, although these latter have not yet been fully 
ested.* Meanwhile it may not be out of place to remark that a 
strong prevailing wind blowing, say, from the north, would increase 
the northerly winds both in frequency and strength, deflecting the 
east and west winds to the south, and probably cut off southerly 
winds altogether. 
WIND-ROSEsS. 
The remainder of this inquiry deals superficially with the varia- 
tions in the four elements of barometric pressure, air temperature, 
* Cordoba lies in the deep valley of the Rio Primero. A few miles to the west 
are some considerable ranges of hills, and 300 miles further are the mammoth 
peaks of the Andes. See ‘‘ Frequencia Relativa Media Annual de los Vientos”’ in 
the Anales de la Oficina Meteordlogica Argentina, vol. ix. p. 353. Few nations 
equal Argentina either in the quality of its meteorological observations, or in the 
sumptuous volumes in which they are published. . 
