(5G4 WINDSOFTHEGLOBE. 



as far south as 40° lat., the winds are N. N. W., N. W., and W. N. W. Crossing 

 the Athmtic, winds in the British Ishinds, in France, and the north of Germany, 

 from the W. S. W. to S. W. ; in Denmark, S. S. W. ; near Bergen, in Norway, 

 S. ; and at Christiansund and Hammerfest, S. S. E. The relation of these winds 

 to the isobaric lines is the same as that which is illustrated by the winds in storms, 

 in their relation to the isobaric lines of these storms. This has been already 

 stated in a paper by the author, published in the Transactions of the Royal Society 

 of Edinburgh, Vol. XXIV. Part I. p. 201, in the following words: 'The wind in 

 storms neither blows round the centre of least pressure in circles, or as tangents 

 to the concentric isobaric curves, nor does it blow directly towards that centre. 

 It takes a direction intermediate, approaching, however, more nearly to the direc- 

 tion and course of the circular curves than of the radii to the centre.' Or, ac- 

 cording to Dr. Buys-Ballot, the angle is not a right angle, but from about 60° 



80°. This relation is usually called ' Buys-Ballot's Law of the Winds.'^ 



"Another well-marked depression is the low summer pressure in the interior of 

 Asia ; with reference to which it is seen from the charts that the winds of Eastern 

 Europe and Western Asia are from N. W. to W. N. W. and W. ; at Ceylon, 

 S. W. ; at Shanghai, S. E. ; and on the Sea of Okhotsk, N. E. ; whilst in the inte- 

 rior, calms generally prevail." 



" The behavior of the winds, as regards the low pressure of North America, is 

 exactly similar to that of the winds in Asia at this season. In all these cases the 

 wind appears to flow round and in upon the space where pressures are low. Even 

 in those instances where the depression over a limifed space is comparatively small, 

 such as in Australia during the summer months, the winds observe the same 

 course with respect to it." 



"A well-known and remarkable diminution of pressure is that of the Antarctic 

 regions ; and though, except in Tasmania and the south of New Zealand, observa- 

 tions are wanting at particular points for a sufficiently long time to give good 

 averages, yet the concurrent testimony of sailors and the inhabitants of these 

 regions all goes to show that, at least on the outskirts of the region, winds are chiefly 

 N. W. or W. N. W. — that is, they appear to flow in upon the space of low pres- 

 sure. The low pressure in the equatorial regions, towards which the trades blow, 

 is an illustration of the same principle." 



"Winds within, or near, a sjiace of High Pressure. — The most prominent illustra- 

 tion of this is the high pressure in the interior of Asia in winter. It is seen from 

 a single glance at the charts that the winds flow out of this space in every direc- 

 tion. The same mttjiow is seen with respect to the less strongly marked, but still 

 very distinct space of high pressure in North America ; owing to the large number 

 of stations available here, this principle is amply illustrated. 



" The next most noteworthy area of high pressure occurs in summer between 

 Africa and North America, out of which also the charts show the winds blowing 

 in all directions towards and round upon the surrounding low pressures." 



"The following mean pressures, in inches, at 32° and sea-level, occur in Australia 

 in June: At Brisbane, Queensland, 30.062; Sydney, 30.116 ; Melbourne, 30.178; 

 Adelaide, 30.132; Freemautle, 30.121; and at Deniliquin, in the interior, on a 



' For Prof. Coffin's determination of this angle, as 65°, see page xsv. 



