May 10, 1901.] 
the triangle ABD proceeded to compute AD 
by well-known trigonometrical relations. I 
do not know why Professor Bigelow should 
find confusion because, in changing from plot- 
ting AD to computing AD, I changed the diag- 
onal from AC to BD. I explained much of 
this in my paper, but, as I was writing for scien- 
tific men, it did not seem to me necessary to 
explain all the elementary processes. 
Further details are given in the Bulletin of 
the Blue Hill Meteorological Observatory con- 
taining my discussion (Annals of the Astro- 
nomical Observatory of Harvard College, Vol. 
XLIII., Part 1, Observations and Investigations 
of the Blue Hill Meteorological Observatory, 
A, Lawrence Rotch, Director). 
The final results as regards the wind circula- 
tion are illustrated in Fig. 3. In this diagram 
the arrows indicate, in the usual way, the 
direction of the resultant wind for different 
portions of the eclipse area, and the lengths of 
the arrows indicate the velocity of the wind. 
The central dark spot shows the area where the 
eclipse was total and the outer continuous cir- 
ele shows the outer limit of the penumbra. 
The inner circle of broken lines shows the 
position of a probable ring of low pressure and 
the outer circle of broken lines shows the 
_ probable position of a ring of high pressure. 
The change of pressure found during the eclipse 
was in perfect accord with this latter conclusion 
derived from the wind circulation, and Pro- 
fessor Bigelow says that the observations of the 
Weather Bureau confirm my curve of pressure. 
The tendency to an anticyclonic circulation of 
the wind near the central area of the eclipse is 
confirmed by the observations of Professor 
Upton and Mr. Rotch in previous eclipses. 
(See Amer. Meteor, Jour., Vol. IV., p. 456, Feb., 
1888 ; also Annals of the Astronomical Obser- 
vatory of Harvard College, Vol. XXIX., p.18, 
1893.) 
I infer that Professor Bigelow does not seri- 
ously question the results as given by me, as he 
says Ferrel’s ‘cold-center cyclonic circulation 
* * * is just the opposite of the result of the 
eclipse observations.’ It is the interpretation 
of the observations to which Professor Bigelow 
objects. 
When I discover a new fact, it seems to me 
SCIENCE. 
749 
proper and even necessary for the advancement 
of science to consider the relation of the new 
fact to earlier known facts and to accepted 
theories and generalizations. In doing this I 
attempt to compare all the various facts and 
theories accessible to me and accept the best. 
In considering the bearings of the eclipse 
data, I read among other things the views of 
Professor Bigelow in the International Cloud 
Report to which he refers. I find myself un- 
able to accept his views of the air circulation in 
cyclones which he derives from the cloud ob- 
servations, nor is his explanation of the diurnal 
change in pressure as an electromagnetic phe- 
nomenon satisfactory. However, in publishing 
results it is usually not possible for an author to 
enter into detail in regard to conclusions with 
which he is not in accord, nor is it best be- 
cause it arouses strife and feeling. It seems 
best to give one’s own conclusions and leave the 
future student to decide between conflicting 
views, as we have done. 
In comparing my eclipse data with the differ- 
ent theories, I found that the results agreed so 
perfectly with certain views expressed by Fer- 
rel concerning the cyclone with a cold center, 
that it leaves me no room for a new theory nor 
an improvement on his. 
Ferrel says, ‘‘The conditions of a cyclone 
with a cold center which are the most nearly 
perfect are those furnished by each hemisphere 
of the globe, as divided by the equator, in which 
the pole is the cold center, and the temperature 
gradient from the pole toward the equator is 
somewhat symmetrical in all directions from the 
center. * * * The center of a cyclone with a 
cold center may, or may not, have a minimum 
pressure, according to circumstances. A cer- 
tain amount of temperature gradient, and of 
pressure gradient which is independent of the 
gyratory motion, as explained in ? 72 in the 
case of the general circulation of the atmos- 
phere, is necessary to overcome the friction in 
the lower strata and to keep up the vertical 
circulation, upon which the cyclone depends ; 
and the pressure gradient, which depends upon 
the temperature gradient and is independent of 
the gyrations, may be such that the increase of 
pressure in the central part due to this cause 
may be greater than the decrease of pressur 
