We have yet many phenomena to investigate by the aid of the theory, and
we will develop them in that order which will best exhibit their mutual
dependence. The solar spots have long troubled astronomers, and to this
day no satisfactory solution of the question has been proposed; but we
shall not examine theories. It is sufficient that we can explain them on
the same general principles that we have applied to terrestrial
phenomena. There can be but little doubt about the existence of a solar
atmosphere, and, reasoning from analogy, the constituent elements of the
sun must partake of the nature of other planetary matter. That there are
bodies in our system possessing the same elements as our earth, is
proved by the composition of meteoric masses, which, whether they are
independent bodies of the system, or fragments of an exploded planet, or
projected from lunar volcanoes, is of little consequence; they show that
the same elements are distributed to other bodies of the system,
although not necessarily in the same proportions. The gaseous matter of
the sun's atmosphere may, therefore, be safely considered as vapors
condensable by cold, and the formation of vortices over the surface of
this atmosphere, brings down the ether, and causes it to intermingle
with this atmosphere. But, from the immensely rapid motion of the polar
current of the solar vortex, this ether may be considered to enter the
atmosphere of the sun with the temperature of space.
Sir John Herschel, in commenting on the theory of Mr. Redfield before
the British Association, convened at Newcastle in 1838,[35] suggested an
analogy to terrestrial hurricanes, from a suspected rotation and
progressive motion in these spots. From their rapid formation, change of
shape, and diameter, this view is allowable, and, taken in conjunction
with the action of the ethereal currents, will account for all the
phenomena. The nucleus of the spot is dense, like the nucleus of a storm
on the earth, and surrounded by a penumbon precisely as our storms are
fringed with lighter clouds, permitting the light of the sun to
penetrate. And, it has been observed, that these spots seem to follow
one another in lines on the same parallel of solar latitude (or nearly
the same), exactly as we have determined the action of the vortices on
the surface of the earth from observation. These spots are never found
in very high latitudes--not much above 30d from the solar equator. If we
consider this equator to be but slightly inclined to the plane of the
vortex, this latitude would be the general position of the lateral solar
vortices, and, in fact, be confined principally to a belt on each side
of the equator, between 15d and 30d of solar latitude, rather than at
the equator itself. This, it is needless to say, is actually the case.
But, a more capital feature still has been more recently brought to
light by observation, although previously familiar to the author, who,
in endeavoring to verify the theory, seriously injured his sight, by
observing with inadequate instrumental means. This is the periodicity of
the spots.
We have already observed, that there is reason to suppose that the
action of the inner vortex of the earth is probably greater than that of
the outer vortex, on account of the conflicting currents by which it is
caused. And the full development of this vortex requires, that the
central vortex or mechanical axis of the system shall be nearly
tangential to the surface. In this position, the action of the central
vortex is itself at a maximum; and, when the planets of the system are
so arranged as to produce this result, we may expect the greatest number
of spots. If the axis or central vortex approaches to coincidence with
the axis of the sun, the lateral vortices disappear, and the central
vortex being then perpendicular to the surface, is rendered ineffective.
Under these circumstances, there will be no spots on the sun's disc.
When, on the other hand, all the planets conspire at the same side to
force the sun out from the mechanical centre of the system, the surface
is too distant to be acted on by the central vortex, and the lateral
vortices are also thrown clear of the sun's surface, on account of the
greater velocity of the parts of the vortex, in sweeping past the body
of the sun. In this case, there will be but few spots. The case in which
the axis of the vortex coincides with the axis of the sun, is much more
transient than the first position, and hence, although the interval
between the maxima will be tolerably uniform, there will be an
irregularity between a particular maximum, and the preceding and
subsequent minimum.
The following table exhibits the solar spots, as determined by Schwabe,
of Dessau:
Year of observation. Groups of spots observed. Number of days.
1826 118 277
1827 161 273
1828 225 282
1829 199 244
1830 190 217
1831 149 239
1832 84 270
1833 33 267
1834 51 273
1835 173 244
1836 272 200
1837 333 168
1838 282 202
1839 162 205
1840 152 263
1841 102 283
1842 68 307
1843 34 324
Previous to the publication of this table, the author had inferred the
necessity of admitting the existence of another planet in the solar
system, from the phenomenon of which we are speaking. He found a
sufficient correspondence between the minima of spots to confirm the
explanation given by the theory, and this was still more confirmed by
the more exact determination of Schwabe; yet there was a little
discrepancy in the synchronous values of the ordinates, when the theory
was graphically compared with the table. Previous to the discovery of
Neptune, the theory corresponded much better than afterwards, and as no
doubt could be entertained that the anomalous movements of Uranus were
caused by an exterior planet, he adopted the notion that there were two
planets exterior to Uranus, whose positions at the time were such, that
their mechanical affects on the system were about equal and contrary.
Consequently, when Neptune became known, the existence of another planet
seemed a conclusion necessary to adopt. Accordingly, he calculated the
heliocentric longitudes and true anomalies, and the values of radius
vector, for all the planets during the present century, but not having
any planetary tables, he contented himself with computing for the
nearest degree of true anomaly, and the nearest thousand miles of
distance. Then by a composition and resolution of all the forces, he
deduced the radius vector of the sun, and the longitude of his centre,
for each past year of the century. It was in view of a little
outstanding discrepancy in the times of the minima, as determined by
theory and observation, that he was induced to consider as almost
certain the existence of a theoretical planet, whose longitude, in 1828,
was about 90d, and whose period is from the theory about double that of
Neptune. And for convenience of computation and reference, he has been
in the habit of symbolizing it by a volcano. The following table of the
radii vectores of the sun, and the longitude of his centre, for the
years designated in Schwabe's table, is calculated from the following
data for each planet:
Long. of
Planets. Masses. Mean distances. Eccentricities. Perihelion.
[JUPITER] 1/1648 494.800.000 0.0481 11d
[SATURN] 1/3310 907.162.000 0.0561 89
[URANUS] 1/23000 1824.290.000 0.0166 167
[NEPTUNE] 1/20000 2854.000.000 0.0088 0
[VOLCANO] 1/28000 4464.000.000
No. of spots in
Dates. Rad. vector. Sun's long. Ordinates. Schwabe's table.
Jan. 1, 1826 528,000 320d + 84 118
" 1827 480,000 339 + 36 161
" 1828 432,000 352 - 12 Max. 225 Max.
" 1829 397,000 38 - 47 199
" 1830 858,000 71 - 86 190
" 1831 324,000 104 - 120 149
" 1832 311,000 144 - 133 84
" 1833 300,000 183 - 144 Min. 33 Min.
" 1834 307,000 220 - 137 51
" 1835 338,000 263 - 106 173
" 1836 380,000 302 - 55 272
" 1837 419,000 337 + 25 Max. 333 Max.
" 1838 488,000 3 + 44 282
" 1839 651,000 29 + 107 162
" 1840 632,000 51 + 188 152
" 1841 680,000 80 + 236 102
" 1842 730,000 105 + 286 68
" 1843 160,000 128 + 322 34 Min.
" 1844 188,000 152 + 339 Min. 52
" 1845 772,000 174 + 328 114
" 1846 728,000 196 + 284 157
" 1847 660,000 218 + 216
" 1848 563,000 240 + 119 Observed. Max.
" 1849 447,000 261 + 3 Max.
" 1850 309,000 283 - 135
" 1851 170,000 323 - 274
" 1852 53,000 41 - 391 Min.
" 1853 167,000 133 - 277
" 1854 315,000 160 - 129
" 1855 475,000 183 + 31 Max.
" 1856 611,000 203 + 167
" 1857 720,000 225 + 276
It is necessary to observe here, that the values of the numbers in
Schwabe's table are the numbers for the whole year, and, therefore, the
1st of July would have been a better date for the comparison; but, as
the table was calculated before the author was cognizant of the fact,
and being somewhat tedious to calculate, he has left it as it was, viz.,
for January 1st of each year. Hence, the minimum for 1843 appears as
pertaining to 1844. The number of spots ought to be inversely as the
ordinates approximately--these last being derived from the Radii
Vectores minus, the semi-diameter of the sun = 444,000 miles.
In passing judgment on this relation, it must also be borne in mind,
that the recognized masses of the planets cannot be the true masses, if
the theory be true. Both sun and planets are under-estimated, yet, as
they are, probably, all to a certain degree proportionally undervalued,
it will not vitiate the above calculation much.
The spots being considered as solar storms, they ought also to vary in
number at different times of the year, according to the longitude of the
earth and sun, and from their transient character, and the slow rotation
of the sun, they ought, _ceteris paribus_, to be more numerous when the
producing vortex is over a visible portion of the sun's surface.
The difficulty of reconciling the solar spots, and their periodicity to
any known principle of physics, ought to produce a more tolerant spirit
amongst the scientific for speculations even which may afford the
slightest promise of a solution, although emanating from the humblest
inquirer after truth. The hypothesis of an undiscovered planet, exterior
to Neptune, is of a nature to startle the cautions timidity of many;
but, if the general theory be true, this hypothesis becomes extremely
probable. We may not have located it exactly. There may be even two such
planets, whose joint effect shall be equivalent to one in the position
we have assigned. There may even be a comet of great mass, capable of
producing an effect on the position of the sun's centre (although it
follows from the theory that comets have very little mass). Yet, in view
of all these suppositions, there can be but little doubt that the solar
spots are caused by the solar vortices, and these last made effective on
the sun by the positions of the great planets, and, therefore, we have
indicated a new method of determining the existence and position of all
the planets exterior to Neptune. On the supposition that there is only
one more in the system, from its deduced distance and mass, it will
appear only as a star of the eleventh magnitude, and, consequently, will
only be recognizable by its motion, which, at the greatest, will only be
ten or eleven seconds per day.