of North America by_ Mr. David Douglas. By John Lindley, Esq.,
F.L.S., &c. &c.
Upon his journey across the rocky mountains in April 1827, in
latitude 52° N., longitude 118° W., at an estimated elevation of
12,000 feet above the level of the sea, the attention of Mr. Douglas
was attracted by a brilliant purple patch amidst the surrounding
snow. On approaching it, he was surprised to find that the colour
which had arrested his eye was caused by the blossoms of a little
plant, from which the superincumbent snow had not yet melted away.
The well-known Saxifraga oppositifolia immediately occurred to his
recollection, and he at first imagined he had either discovered that
species, or one nearly allied to it; but upon a closer inspection,
he perceived that it was no Saxifraga, but a genus apparently new.
Specimens having been submitted to me for examination since Mr.
Douglas’s return, the following description has been drawn up:—
The plant forms a thick tuft consisting of numerous perennial
branched stems, the lower of which are covered with the persistent
decayed leaves and fruit of previous summers. The _stems_ are round,
bright purplish brown, covered with scattered, rigid, branched,
short hairs, and densely clothed with opposite spreading leaves.
The leaves are a dull glaucous green, semi-amplexicaul, [p384]
linear, obtuse, about five lines long and three-quarters of a line
broad, so closely covered with hairs like those of the stem, that
the whole epidermis is hidden. Their veins are concealed by the
hairs; but if the latter are removed, they appear to consist of a
thickened mid-rib, and a few nearly simple spreading venæ primariæ.
The _flowers_ proceed from the axillæ of the upper leaves, from
three to six on each little branch; at first they are sessile, but
their foot-stalks subsequently lengthen by degrees until the fruit
is ripe, when they are from three-quarters of an inch to one inch in
length, and covered with the same sort of hairs as the leaves and
stem. The _calyx_ is hairy in like manner, obconical, angular, with
five equal erect narrowly triangular teeth, about the length of the
tube. The _corolla_ is of a vivid purple colour, infundibuliform,
wholly destitute of pubescence; the _tube_ is a little ventricose
and rather longer than the calyx, its whole length being about three
lines; the _limb_ is spreading, five-parted with cuneate, oblong,
obtuse, segments; the orifice is guarded by five transversely linear
calli, placed under each sinus, and corresponding to the same number
of external depressions of the neck of the tube. The _anthers_ are
linear oblong, nearly sessile, opposite the segments of the corolla,
and a little enclosed within the tube. The _ovarium_ is superior, of
an obovate figure, one-celled, with a central, free, fungilliform
placenta, the lower edge of which has five teeth corresponding to an
equal number of peltate ovula; the _style_ is filiform, as long as
the tube of the corolla, and continuous with the ovarium; _stigma_,
a minute depressed cup. The _capsule_ is of a cartilaginous texture,
surrounded by the persistent calyx; one-celled, with five recurving
valves; the _seeds_ are two, peltate, oblong, convex on the outside,
concave in the inside, dark brown, covered closely with minute
dots or depressions; four only having been found, their internal
organization has not been determined.
Hence it appears that, with the exception of the interior of the
seed, the whole structure of the plant is determinable: it is also
obvious that it is referable to Primulaceæ, of which it possesses
all the characters. In fact it is closely akin both to Primula and
Androsace. From both these genera, however, [p385] its ovarium which
exhibits the greatest instance of reduction of ovula yet known in the
order, and its dispermous capsule, with oblong concave seeds, readily
and essentially distinguish it.
I have, therefore, named it after its indefatigable discoverer,
whose active and successful researches in its native country, richly
entitle him to the distinction.
DOUGLASIA.
NAT. ORD. _Primulaceæ_; _inter_ Primulam _et_ Androsacen.
_Calyx_ obconicus, angulatus, 5-dentatus. _Corolla_ infundibularis,
tubo ventricoso, limbo plano 5-partito, fauce callo lineari sub
utroque sinu. _Ovarium_ uniloculare placentâ centrali liberâ
pedicellatâ fungilliformi, margine 5-dentato; ovula 5 dentibus
placentæ opposita. _Capsula_ vestita, unilocularis, 5-valvis.
_Semina_ duo concava scrobiculata.—Cæspes _suffruticulosus_ (Americæ
borealis), foliis _indivisis_, pube _rigidâramosâ_, _floribus
axillaribus solitariis_.
Sp. 1. _Douglasia nivalis_.
_A Description of the Aurora Borealis seen in London on the Evening
and Night of the 25th of September, 1827; with Critical Remarks upon
other Descriptions of the same, and previous Appearances of the
Meteor, both in the Northern and Southern Hemispheres_. By E. A.
Kendall, Esq., F.S.A.
On the evening and right of the 25th of September last, the horizon
of the metropolis, toward the north, and toward the north-west and
the north-east, exhibited a remarkable display of the meteor or
phenomenon called, after the example of the Italian philosopher
Gassendi, Aurora Borealis.
The weather, for many days preceding, had been mild, with alternate
sunshine, clouds, and showers. The wind had been generally in the
west and south-west quarters; though on the 18th and 19th it was in
the north-west, and on the 20th in the north-east. The barometer,
at three o’clock in the afternoon, had stood at from 30° 40′ to 30°
20′, to which latter height it had descended on the 20th; and, from
that day to the 25th, it had remained, at 29° 90′ and 29° 75′. The
thermometer, at the same hour, between the 14th and the 20th, had
ranged between 65° 6′ and 59° 2′; and it stood, on the 25th, at 59°
6′, with the wind in the south-west. The sky, toward the zenith, on
the evening of that day, was [p386] partially clear, and partially
covered with shifting clouds. On the north, and on the west and east
of north, heavy and stationary clouds blackened the whole horizon, to
an elevation of more than five degrees; and the southern hemisphere
was dark with dark clouds from the horizon to the zenith.
* * * * *
I. By some, the Aurora was seen from the time when the sun was
set; but the first appearance in the heavens, which attracted the
attention of the present writer, whose situation at the moment shut
out from him the horizon upon all sides but the west, was that of a
certain breadth of red or copper-coloured light, or of light of a
colour nearly resembling that reflected by an ordinary conflagration
of buildings, pointing upward from the west. The colour, indeed,
was dissimilar from that which is usual upon the occurrence of a
fire on a cloudy night; yet, in the absence of any other immediate
explanation, he should not have hesitated so to understand it,
except for the figure within which it was circumscribed, and which,
instead of being diffusive, and less and less conspicuous toward
its extremities, or rounded in its outline, like masses of ruddy
smoke, had the peculiarities of an equal breadth, rectilinear
sides, a square top, and sharp outlines. Its height was continually
increasing; but not even that phenomenon, nor even the curve to the
eastward, across the heavens, and which it presently began to add to
its figure, were appearances absolutely to dissipate the illusion of
the existence of a fire; and it was scarcely, therefore, till this
breadth of colour, throwing itself entirely over the heavens, and
descending, at its projected extremity, toward the east, formed an
arch, of which, perhaps, the elevation was seventy degrees, (which
was not the work of many minutes, the motion, at the same time, being
visible, but of moderate rapidity,) that its real character of a
natural phenomenon distinctly impressed itself upon the mind of the
present writer, its observer. While this, however, was proceeding,
the road which he was pursuing had brought him more into view of
the north-western and northern horizon; and, then, the light in the
north, and to the west of north, which, from behind the clouds that
lined the horizon, seemed like the light of a rising moon, or of
the [p387] breaking day, together with the vertical projection of
rays of light, beneath and above the arch, removed every doubt as to
the cause of the appearance, by demonstrating its connexion with an
Aurora Borealis.
It was now about a quarter past eleven o’clock. The sky, beneath
the lower or inner edge of the arch, was clear and star-light, and,
through the contrast created by the ruddy colour placed against
it, appeared of a lively blue. The upper edge of the arch, in the
meantime, was relieved only by the dark gray of the clouds, which,
with more or less continuity, overhung the upper part of the heavens.
But these latter were now dispersing; the cloudless zenith, which
presently afterwards disclosed itself, was now progressively and
swiftly preparing; and, as the clouds moved and fled, the outlines of
the arch lost their sharpness, the colour changed, from that of fire
or of copper, to something more or less of purple or of the rose; it
spread itself in the vapour, and with the vapour vanished.
* * * * *
II. But this was only the curtain of the stage, behind the folds of
which the true scene had its existence. This latter, still concealed,
to a certain and uniform height, by a parapet, as it were, of dark
and unbroken clouds, consisted, first, in the ground of white light,
already described as resembling that of a sky in the midst of which
clouds shut out the disk of the moon, or rather that in which the
rising sun is just about to appear; and, secondly, in a range of
columns, or fountains, or jets of light, more coloured than the
ground, which, rising from behind the ridge or parapet of clouds, and
from and in the midst of the white light, formed, together, not the
figure which would have been produced by their uniform convergence
toward the zenith, but one which bore some resemblance to that
assumed by the sticks of a fan, or still more to the appearance
of stalks in a flower-basket, or in a sheaf of corn. For, in this
manner, the column, which, in general terms, may be called the
central one, and which arose in the due north, was vertical, and
therefore projected toward the zenith; while those which extended
from it upon either side, that is, toward the west or toward the
east, gradually inclined more and more [p388] toward the horizon on
their respective sides; and, as to the outer columns on the east,
inclined, not in rectilinear figures, but in curves more or less
decided. In these columns or coruscations several particulars were to
be remarked.
1. That, within the space of from one hour to two, the whole group
appeared to traverse the horizon together, from the west of north to
the east of north, as if upon one movable base, or as if the source
of their appearance became gradually exhausted to the west of north,
and grew gradually into activity upon the east of north; alternatives
of explanation, however, which might materially affect the theory of
their production. During the whole change, in the meantime, the north
preserved its splendour, appearing uniformly as the focus of the
fire, or as the pivot of the machine, or as the well from which all
else was supplied. The change consisted in the appearance of columns,
of more or less magnitude, strength, and brightness, more or less
advanced from the north toward the west, or from the north toward the
east; but the north, during all this variation, suffered no other
change than this, that whereas, in the beginning of the evening, the
greater portion of columns rose to its west, while, in the latter
part of the night, the greater portion arose to its east. But,
besides this general configuration, and this united motion of the
meteor, there was to be observed, in the several columns themselves,
both the variations of colour which distinguished one from another,
and the irregular and independent movement of each, always in the
direction of its length or altitude, and situate in the interior,
as it were, of its body; and also that peculiarity of form which
distinguishes these coruscations from all other luminous appearances.
2. The colours of the columns, in that part of their height which
is nearest their base, and where, as a ground, they had only the
white light of the horizon, by which, and by their motion, and it
should, perhaps, be added, their vividness, they were distinguished,
is a point upon which the writer speaks with some hesitation, and
with respect to the more close observation of which he could like
to enjoy a second opportunity of beholding the phenomenon. The
variety and richness, and sometimes the terrible grandeur, of the
colours [p389] exhibited in the Aurora Borealis, is the constant
theme of spectators and naturalists; and, upon the late occasion,
an observer, apparently of more regularly scientific habits of
pursuit than himself[120], has particularly insisted upon a column,
of a violet colour, rising west of north, and the place of which he
thinks corresponding with that of the _magnetic pole_; a coincidence
from which, as it may seem, he would believe a confirmation of the
_magnetic theory_ of the production of the Aurora to be obtained.
In setting down the present description, the writer tasks himself
to the most faithful description of what he actually saw, and
suppression of all desire to support or condemn a theory, of which
his mind is capable; and by those rules, therefore, the whole
statement will be guided. His description already differs from that
of some of his fellow-witnesses, as will be expressly considered
below; but he confesses that while, in point of persuasion, he much
inclines to the idea, that all the light displayed by the Aurora is
in itself white, and only tinctured to the eye of the spectator by
the atmospherical medium through which it is seen; and while, with
respect to all those deeper colours, whether crimson or purple, or
blood-colour, which appal the superstitious, and are described by the
picturesque narrator as exhibiting the terrible in matters of vision,
he judges it supposable that the whole machinery consists in the same
interposition of vapour, near the horizon, which so often gives to
the sun and moon themselves the appearance of being coloured like
blood: while, therefore, he still adheres to his opinion, that the
colours ascribed to the Aurora are wholly extrinsic; and, to borrow
the words of a scientific writer, “dependent upon the medium through
which they are seen;” he is obliged to acknowledge, that it did
appear to him, that the several columns, in truth, were yet variously
coloured, of pale, but bright and pleasing colours, from a pale
yellow to a pale pink and a pale violet, and this in the direction
of their height or length,—a phenomenon which wholly excludes, as
to those columns and their colours, the influence of an interposing
medium, the effect of which would be perceived horizontally, and
across the whole range of columns, or part of the range, and not
[p390] vertically nor obliquely, according to the direction of each
column, and within the limits of its sides. He confesses, also, that
he did take notice of the pale, but bright violet-coloured column,
distinguished also by its breadth and height, and situated to the
west of north; but which column, he is surely right in adding,
ultimately moved, with those next to it, toward the north. He
distinctly and pointedly observed, at the same time, that the columns
which stood due north were always white, and that the colours of
the other columns appeared to strengthen in proportion as they were
distant from the due north, either west or east; and he came to a
fixed conclusion, while the phenomenon was under his eye, that, to
his judgment at least, the strength of the fire, so to say, was in
that point of the horizon which lay due north; and that there was a
diminished brightness, with a proportionable increase of colour, to
the right and left.
3. As to the separate movements of the columns, these, in the first
place, were quick, and forced upon the eye, while the movement which
gradually deployed or advanced the right wing of the celestial
arm, and gradually contracted or withdrew the left, was slow, and
perceived only by its results; and, in the second place, while these
latter were parallel to the horizon, the former were either vertical,
or in the oblique or curved direction of the bodies of the columns.
But this motion consisted either in vibration, or in irregular but
alternate projections and contractions; and the motion of each
column, as has been said, was independent on that of others. Rarely,
two adjoining columns were in motion at the same time. Almost always
the moving column or columns were seen to start from the midst of
others, which, for the time, were quiescent, but which had had their
turn before, and would presently have it again. What eminently struck
the writer, however, was the internal motion of that to which he
cannot allow himself to give another name than that of the apparent
luminous material of the columns. It seemed to him as if the volume
of each column or coruscation was itself composed of parallel lines
of luminous matter, arranged in the direction of the column, and
every one of which was separately the subject of movements similar
to those of the entire [p391] column, or entire bundle of lines; or
as if the whole column were like the stalk of a plant, and filled
with upright and luminous fibres, or like a skein of thread, drawn
vertically or obliquely, and of which each particular thread should
have particular motion in the direction of the whole; or (what he
thought the comparison which proclaimed the very nature of the
material of the columns) like fountains, or jets of water in the sun,
in which every particular particle should be moving in the general
direction of the jet, and yet each moving and shining for itself.
4. And this apparent nature of the substance of the columns or
coruscations allies itself to what finally regards them; namely,
their form. In this description, they have hitherto been spoken of by
the name of columns or pillars; and the similitude, which that name
suggests, is justified by the general figure of all the lower parts
of their bodies, which, unlike the figure of rays of light on the one
hand, and unlike that of flames of fire on the other, is a tall or
lengthened object, of small comparative diameter or breadth, and of
which the sides consist in right and nearly parallel lines. But, by
the English, these columns, pillars, or coruscations, were anciently
called so many _burning spears_; and they have also received the
names of _streamers_ and _pencills_[121], which two latter, in the
history of appurtenants of war, signify long and narrow, and pointed
banners or flags. Their similitude to flags is excusably fancied from
their quick, capricious, and irregular motions, but their likening to
“spears,” is that which may claim to be thought the most felicitous,
as to the true conception of their form, as it is also that, the idea
of which contributes to render the phenomenon the most fearful in the
[p392] survey of ignorance and superstition. But the SPEAR-SHAPE
is descriptive, because the coruscations, unlike rays of light, and
unlike flames of fire, have neither the obtuse figure of a pyramid,
nor the acute one of an obelisk, upright or reversed; but, after
rising, through almost their whole height or length, of an equal or
nearly equal diameter, terminate in a point which is formed, not of
right lines, like the point of a dagger, but of curved lines, so as
to form the rounded point of a spear, or that figure which is so
familiar to botanists, as spoken of “spear-shaped” leaves. A ray of
light, in whatever direction it is thrown, broadens, with right-lined
sides, from the first point of its departure, to the furthest stretch
of its projection; a flame of fire points uniformly upward, with the
same regularity of form, excepting only as it is liable to undulation
from the motion of the atmosphere; but, the columns, spears,
streamers, or coruscations of the Aurora Borealis, have no form but
that under review.
5. About half-past eleven o’clock, or nearer to twelve, several
powerful columns shot toward the zenith; while, to the east of north,
others were at once curved in their form, and projected in an angle
of about thirty degrees with the horizon. But while, upon the west
of north, the sky, above the ridge of clouds, was entirely clear, so
that, there, the columns played upon a ground which formed a slight
contrast with themselves, here, the clouds were still heavy, and
the columns behind them appeared, in consequence, of a fiery red,
deepening as they approached the outer edge of the whole display, at
which was the sharpest outline, contrasted in the distinctest manner
with the dark sky. The light upon that side called to the mind of
the writer the “dunnest smoke of hell,” of Macbeth; while, as to its
outer line, as seen from the east end of Pall-mall, the sides of the
stone spire of St. Martin’s church, which rose to the eastward of
it in the sky, were not more sharply defined; the dark intervening
sky affording relief to both, though not equally so, upon account of
the superior brightness of even the obscured columns. But, in taking
leave of this columnar, or spear-like, and main part of the Aurora,
it may be permitted to add, that, in those tapering forms, together
with their motions, (though the comparison [p393] may still be
sufficiently remote and fanciful,) it was easy to discern the origin
of their having been resembled to weapons of war; that is, to the
spears of an army, raised, lowered, laid at angles, and gleaming,
glittering, crossing, and clashing in battle. And equally, too,
from their quick, varied, and separate, and, as it were, whimsical
motions, might they reasonably receive, in their milder displays,
and in moments of more peaceful and cheerful association, the very
different name of _merry dancers_!
* * * * *
III. Though, as will presently be found, it is the ruling idea of
the present writer, that the Aurora Borealis is a single object,
its appearance, when unmodified by the accompaniments of clouds or
fogs, being merely that of its own coruscations, playing in the
free expanse, yet for the purposes of analytical description and
contemplation, it is here thought convenient to divide it into
the three parts in which, through the temporary and accidental
intervention of the coloured arch before-mentioned, it appeared in
the night now in recollection. These three supposititious parts,
then, may be understood as follows: first, the arch, belt, or band
which was temporarily thrown across the heavens; second, the main
body of the coruscations below the arch; and third, the coruscations
above it, and in or near the zenith. It is of these only that it
remains to speak.