590 
(not west) to latitude 30°, thence south and west 
(not east) to the equator, in which region it as- 
Circulation we warm Centerbycloie. 
SEN 
o \ 
Circulation in cold Center Cyclone 
Isobars tre warm Center Cyclone 
Ts0baris te cold Center Cyelone. 
Lsobars cre Clay tors HelepseGreloné i 
SCIENCE. 
[N. 8S. Vou. XIII. No. 328. 
cends, etc. Thus, page 837, ‘‘ This vertical 
circulation, as in the case of the ordinary cy- 
clone, gives rise to a cyclonic motion in the in- 
terior (that is, to the place where the gyration 
reverses from + v to —v) and an anti-cyclonic 
in the exterior part.’’ Cyclonic rotation is 
against the hands of a watch, looking down 
upon it, and anticyclonic is with the hands, so 
that in warm and in cold-center cyclones the 
rotation is cyclonic near the center, and anti- 
cyclonic beyond a certain circle of reversal. In 
the warm-center cyclone the motion is ascend- 
ing and inward near the surface in the interior 
and descending in the exterior; in the cold- 
center cyclone these motions are reversed, but 
the direction of rotation about the pole is not 
changed. Ferrel’s formule, diagrams, and dis- 
cussions agree in this throughout his works ; 
indeed, there could be no other interpretation 
of them on mechanical principles. He says, 
C.5. O., page 203, ‘Such areas of high barom- 
eter (referring to the high pressure area pro- 
duced by the overlapping of two adjacent cy- 
clones) are usually called anticyclones, and 
the air does in some manner move around them 
in a direction contrary to that of a cyclone, but 
this does not arise froma central area of greater 
cold, for it has been shown that such a condi- 
tion would give rise to a cyclone and not to an 
anticyclone, and that the latter would be en- 
tirely at variance with fundamental and well, 
established principles of mechanics.’’ 
When the temperature gradients are very 
steep and there is much friction on the surface, 
a small secondary maximum pressure may de- 
velop in the center of the cold-center cyclone. 
In the case of the eclipse the temperature gra- 
dients were feeble, and the wind velocity v 
small, upon which the friction-force —k.v de- 
pends, so that it could not happen under the 
circumstances of the eclipse phenomenon. 
Now by comparing Clayton’s diagram, Fig. 
5, Plate II., for the wind direction, we find 
a true anticyclonic configuration at the center, 
and this rotates in the opposite direction to 
that required in the cold-center cyclone; if 
wind stream lines were to be drawn from the 
center outward at right angles to those con- 
tained in the Clayton diagram, we should 
then obtain a cold-center cyclonic circulation, 
