200 Scientific Proceedings, Royal Dublin Society. 
proportion present with strong winds, and 3°78 when the air was 
only feebly agitated, the observations being made at mid-day. 
Reiset (at Dieppe) says:—‘‘'The great S.W. wind, which 
prevails in our country, often brings with it rain or tempests: it 
usually leads to a regime of minima.” 
Schulze (at Rostock) was of the opinion that N.H. winds from 
thecontinent increased the amount, while S. W. winds decreased it— 
the latter effect being due to absorption by the sea. 
Farsky (at Tabor in Bohemia) also maintained that an increase 
occurred with N.E. winds, and with northerly winds also, while 
those from the N.W. and S.W. lowered the amount. 
Hasselbarth and Fittbogen (at Dahme) state that the figures 
obtained by them show an intimate connection between the force 
and direction of the wind, and the amount of atmospheric carbonic 
anhydride. According to them, an increase in force, no matter 
from what direction, invariably decreasesthe amount. After high 
winds and storms the quantity almost always increases. When 
this does not occur it is due to the maintenance of higher winds 
than usual or a change in their direction. 
Spring and Roland (at Liége) also considered that the amount 
of carbonic anhydride varied with the direction of the wind, the 
variations being caused by the nature of the districts traversed by 
the latter. Maxima were observed with N. and N.W. winds, 
which carried air from the town to the laboratory, while a third 
maximum was observed with the S.S.W. wind, which brought air 
from the great industrial centre of Seraing. On the other hand, 
the minimum was found with a N.N.W. wind coming from the 
elevated plateau of Hervé, celebrated for its pasturage, and a 
second minimum, but not so low as the first, with the S.H. wind 
from the elevated plateaus of Spa and Stavelot; this wind, how- 
ever, passing over a manufacturing centre before arriving at the 
laboratory. As to the effects of force of wind, Spring and Roland 
were of opinion that the amount of carbonic anhydride decreased 
with strong winds, and increased with stagnation of the air. 
Petermann and Graftiau, in a series of observations (at Gembloux 
in Belgium) extending continuously over a period of two years 
(May, 1889, to April, 1891), were unable to trace any decided effect 
of direction of the wind. Neither a régime of continental air 
currents nor one of maritime winds, they say, influences the amount 
