132 
figures in a known period, by combining them according 
toa slightly different law, will show at once, not only that 
we have not the right period, but what that exact period 
is. For example, take 27 figures in a definite progression 
and arrange them according to a period of 27 1/3 days, 
average each 6 periods in succession by themselves and we 
shall find that each group has its maximum point retarded 
by two days from the preceding. In meteorologic work 
it is better to average in groups of 6 and 7 periodsin each 
year, as this eliminates the seasonal effect. 
The best data to study the sunspot period are con- 
tained in photographs of the suntaken at Greenwich and 
in India, which together give a superb record for nearly 
every day of the year. We shall avoid difficulties if we 
average these figures in groups of ten rotations each, and 
we would naturally expect to find the influence in each 
group. Ifwe do not finda thread running through all 
these groups, it would be pretty good evidence that we 
cannot get at the influence, evenif there is any, in this 
way, but that it was either entirely masked by other 
forces, or else was too insignificant to show itself. 
I have arranged the sunspot areas from April, 1881, to 
1889 in different periods of 25, 25.5, 27 and so on days 
and in groups of ten rotations each, and have projected 
curves from these. The curves for the period of 27 days 
are given here. These curves present the actual data 
without smoothing or rounding, as this best shows the 
precise fluctuations. The light vertical lines show the 
first, fourth, eighth, etc., day of therotation. Hach group 
of ten rotations has a Roman numeral at the end, and the ~ 
last (1) isthe mean of the ro groups, or of roo rotations. 
We see at a glance that these groups have no common 
thread at any specific day of the period running through 
all, and this shows that nothing can be hoped for in this 
study unless we can first eliminate some of the influences 
which mask the real effect at the solar meridian. The 
more reasonable hypothesis is that there is no definite 
period in this influence. 
But this is not all. The last curve (1) shows how ex- 
ceedingly slight the effect must be, and afew more groups 
would have practically removed even these slight fluctua- 
tions. Again, we see that the maximum and minimum 
points in (T) are often due to a marked fluctuation in one, 
or at most in two, of the individual groups, for example: 
the maximum point in(T) near the 16th day is due en- 
tirely to the marked fluctuation in II. at the same day, 
and, if that group, or perhaps two rotations of the ten in 
the group, were omitted, this fluctuation would practically 
disappear. It would seem as though the evidence was 
conclusive that these crests and hollows in (Tl) are en- 
tirely fortuitous and do not show any influence recurring 
from rotation to rotation or any physical connection in 
the fluctuations of the different groups. 
Precisely the same reasoning will apply with still greater 
force to similar studies of meteorologic elements. Here 
we have a great many local causes modifying the original 
cosmical influence, and these must be eliminated first. 
The temperature of the air, for example, is affected by 
the onward progress of hot and cold waves, by clouds, 
which serve to diminish the sun’s heat by day and _ terres- 
tial radiation by night, by moisture, by rainfall, by wind, 
etc. Before we could attempt a study for periods in this 
element, it would be necessary to take out these effects 
or to show that they are overborne by the greater cosmic 
influence. 
I do not think that this negative result should lead us 
to conclude that extra terrestrial forces, aside from heat, 
have no marked effect upon our weather, but simply that 
this is not the proper method of getting at these influences. 
The evidence of such effects is overwhelming, and we may 
hope for the greatest advances in meteorology in the near 
SICIUEIN Cle. 
Vol. XXIII. No. 579 
future along these lities of research, that is, in developing 
extra terrestrial influences. Whence comes the enormous 
amount of electricity stored in the atmosphere at heights 
of 5,000 to 10,000 ft.? An answer to this single question 
would be of inestimable value to meteorology. It would 
seem to be a direct effect from the sun. ‘lhe present 
lively discussion and most careful studies upon the in- 
fluence of electricity in vapor condensation are gratifying 
and give an earnest of what may still be hoped for. The 
recent pilot balloon ascensions in Paris up to nearly 10 
miles open up anew field for the meteorology of the 
future. These conditions at ro and 15 miles must be due 
to extra terrestrial forces. It is claamed by many that 
the heat of the sun has no effect upon the air at these 
enormous heights, and yet, there are indications of most 
marked fluctuations of temperature on the passage of high 
and low areas. It has been well established that on the 
Ps a eae 
+ 
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Corr ea ans art tee, 
Ee saa) 
approach and passage of a low area over Pike's Peak, 
Sonnblick and other high mountains there is a marked rise 
in temperature, and the fluctuation is generally greater 
above than below. 
On Mar. 21, 1893, in Paris, a balloon reaching nearly 
ten miles in the centre of a high showed a diminution of 
1- F. in 310 ft. Sep. 17, the same balloon near a low 
showed a diminution of 1° F. in about 380 ft., or pecisely 
the same law as on mountains. 
Meteorology has been woefully hampered in the past by 
the theory that all weather changes are due to the heating 
or cooling, and flowing, or drifting of masses of air com- 
paratively near the earth. Let us look away from these 
minor conditions and get an insight into the real causes 
of these conditions, or what is back of them. Let us 
broaden our view and see how extra terrestrial forces are 
continually acting upon the upper limits of our atmosphere 
as well as upon the lower layers and are feeding or generat- 
ing our storms, cold waves, etc. Let us cut loose from 
the idea that all our weather conditions are borne along 
by air currents, for it is plain that this is impossible, since 
