In August 1782 the Herschels removed to Datchet. Their new home was "a
large neglected place; the house in a deplorably ruinous condition, the
garden and grounds overgrown with weeds." Nor were the domestic
arrangements more favourable. For a fortnight the little family were
without a female servant; and an old woman, the gardener's wife, showed
Miss Herschel the shops, where the high prices of every article, from
coals to butcher's meat, appalled her. But of these inconveniences
Herschel took no account. Enough for him that he was released from the
drudgery of teaching, and free thenceforth to devote himself to the
heavens and their wonders. A man whose thoughts are always with the
stars can hardly be expected to trouble himself about the price of
tallow-candles! Were there not capacious stables in which mirrors of
any size could be ground; and a roomy laundry capable of easy conversion
into a library, with one door opening on a large lawn, where the "small
twenty-foot" was to take its stand? Compared with advantages such as
these, what mattered the scarcity of "butcher's meat"? Herschel
laughingly assured his sister that they could live on eggs and bacon;
which, he confidently asserted, would cost next to nothing, now that
they were really in the country!
And so he settled down to a life of quiet, industry at Datchet; his
admirable sister being formally adopted as his assistant and secretary.
Never had master a more devoted, a more enthusiastic, or a more
intelligent servant! She shared in all his night-watches, with her eye
constantly on the clock, and the pencil in her hand; with unerring
accuracy she made all the complex calculations so frequently required;
she made three or four copies of every observation in separate
registers, co-ordinating, classifying, and analyzing them. If the
scientific world, says Arago, saw with astonishment the unexampled
rapidity with which Herschel's works succeeded one another for many
years, they were greatly indebted for this affluence of production to
the affectionate ardour of his sister Caroline. Her enthusiasm never
failed; her industry knew no check; and her brother's fame was dearer to
her than life.
In one of her letters she describes with graphic simplicity the
"interior" at Datchet:--
"I found that I was to be trained for an assistant-astronomer;
and by way of encouragement, a telescope adapted for 'sweeping'
(or rapidly surveying a wide extent of space), consisting of a
tube with two glasses, was given [to] me. I was to 'sweep for
comets;' and I see by my journal that I began August 22nd,
1782, to write down and describe all remarkable appearances I
saw in my 'sweeps.' But it was not till the last two months of
the same year that I felt the least encouragement to spend the
starlit nights on a grass-plot covered with dew or hoar-frost,
without a human being near enough to be within call. I knew
too little of the real heavens to be able to point out every
object so as to find it again without losing too much time
by consulting the Atlas. But all these troubles were removed
when I knew my brother to be at no great distance, making
observations with his various instruments on double stars,
planets, and the like; and I could have his assistance
immediately when I found a nebula, or cluster of stars, of
which I intended to give a catalogue. I had the comfort to
see," she continues, "that my brother was satisfied with my
endeavours to assist him when he wanted another person either
to run to the clocks, write down a memorandum, fetch and carry
instruments, or measure the ground with poles,--of which
something of the kind every moment would occur."
The conscientious care and assiduous industry with which Herschel made
his measurements of the diameter of the Georgium Sidus (now called
Uranus), and his interesting observations of other planets, of double
stars with their coloured light, of cometary and nebulous appearances,
were truly remarkable; as may be seen by the various papers which
he wrote at this time for the Royal Society. In addition to all this
labour, he perfected a twelve-inch speculum of vast magnifying power
before the spring of 1784; and many hours were spent at the
turning-bench, as not a night clear enough for observing ever passed
without the devising of improvements in the mounting and motion of
the various instruments then in use, or the test and trial of
newly-constructed "eyepieces," most of which were executed by Herschel's
own hands. "Wishing to save his time, he began to have some work of that
kind done by a watchmaker, who had retired from business, and lived on
Datchet Common; but the work was so bad, and the charges [were] so
unreasonable, that he could not be employed. It was not till some time
afterwards, in his frequent visits to the meetings of the Royal Society
(made in moonlight nights), that he had an opportunity of looking about
for mathematical workmen, opticians, and founders. But the work seldom
answered expectation, and it was kept to be executed with improvements
by Alexander during the few months he spent with us."
* * * * *
In July 1783 Herschel began his observations with his large twenty-foot
telescope, though it was in an unfinished state; and his sister watched
and waited with much apprehension when she knew him to be elevated some
fifteen feet or more on a temporary crossbeam instead of a safe gallery.
Here it is needful to explain, perhaps, that these huge astronomical
telescopes are not used like ordinary glasses, to one end of which the
observer applies his eye; the objects towards which the tube is directed
being thrown upon a large mirror, which is attached to it externally
at some distance from the ground. The observer, therefore, needs to
be mounted on an elevated platform or gallery, from which he can
conveniently inspect the mirror. One night, in a very high wind,
Herschel had scarcely descended from his station before the whole
apparatus came down; and his sister was in continual apprehension of
some serious accident. One such, indeed, occurred, and to herself. The
evening of the 31st of December had been cloudy, but as a few stars
shone forth about ten o'clock, hurried preparations were made for
observing. Herschel, standing at the front of the telescope, directed
his sister to make a certain alteration in the lateral motion, which was
done by machinery, on which the point of support of the tube and mirror
rested. At each end of the machine or trough was an iron hook, such as
butchers use for suspending their joints of meat; and having to run in
the dark across ground covered a foot deep with melting snow, Miss
Herschel fell on one of these hooks, which entered her right leg above
the knee. To her brother's injunction, "Make haste!" she could answer
only by a pitiful cry, "I am hooked!" He and the workmen hastened
immediately to her assistance, but they could not disentangle her
without leaving nearly two ounces of her flesh behind. For some weeks
she was an invalid, and at one time it was feared that amputation might
be necessary.
* * * * *
Not satisfied with the magnifying power of any of the instruments he
had hitherto constructed, Herschel resolved, in 1784, to attempt a
forty-foot telescope. Such a work, however, was far beyond his limited
private resources; and he did not venture to undertake it until promised
a royal bounty of £2000. Then he removed from Datchet to Clay Hall, Old
Windsor; and again, in 1786, to Slough, where he finally settled, and
succeeded in erecting a commodious and well-equipped observatory. "We
may confidently assert," says Arago, "relative to the little house and
garden of Slough, that it is the spot of all the world where the
greatest number of discoveries have been made. The name of that village
will never perish: science will transmit it religiously to our latest
posterity."
At Slough, as at Datchet, prevailed the most enthusiastic industry; and
the house was soon as full of well-ordered labour as a bee-hive. Smiths
were kept constantly at work on different parts of the new telescopic
leviathan; and a whole troop of labourers was engaged in grinding the
tools required for shaping and polishing its mirror. Had not a cloudy or
moonlight night sometimes intervened, Herschel and his sister must have
died of sheer exhaustion, for they toiled with unremitting ardour both
day and night. With the morning came the workpeople, of whom no fewer
than between thirty and forty were at work for upwards of three months
together: some employed in felling and rooting out trees, some digging
and preparing the ground for the bricklayers, who were laying the
foundation for the telescope. Then there were the carpenter and his men;
and, meanwhile, the smith was converting a wash-house into a forge, and
manufacturing complete sets of tools for his own share of the labour.
In short, the place was at one time a complete workshop for the
manufacture of optical instruments; and it was a pleasure to enter it
for the purpose of observing the fervour of the great astronomer, and
the reverent attention given to his orders.
It is impossible not to refer here to the sisterly devotion of Caroline
Herschel, who was in every respect worthy of her noble-minded,
tender-hearted, and enthusiastic brother.
She stood beside him to the last, sharing his labours, brightening his
life. In the days, says her biographer, when Herschel gave up a
lucrative career that he might dedicate all his energies to astronomical
pursuits, it was through her care and thriftiness that he was spared
from the unrest of pecuniary anxieties. As she had been his helper and
assistant during his career as a popular musician, so she became his
helper and assistant when he gave himself up, like the Chaldeans of old,
to the study of the stars. By dint of a resolute will and a love that
shrank from no sacrifice or exertion, she acquired such a knowledge of
mathematics and calculations, mysterious as these generally seem to the
feminine mind, that she was able to formulate with exactness the result
of her brother's researches. She never failed to be his willing
fellow-labourer in the workshop; she helped him to grind and polish his
mirrors; she stood beside his telescope, in order to record his
observations, during the dark and bitter mid-winter nights, when the
very ink was frozen in the bottle. It may be said, without exaggeration,
that she kept him alive by her care: thinking nothing of herself, she
lived for him, and him alone. She loved him, she believed in him, she
aided him with all her heart and all her strength. Her mental powers
were very considerable; and undoubtedly she might have attained to
eminence on her own account, for she herself discovered no fewer than
eight comets. But she shunned self-glorification; she desired to live in
her brother's shadow; she worked for him, never for herself; and in her
elevated character no feature more strongly demands our admiration than
her heroic though unconscious self-denial. Happy the man who has such a
sister; happy the sister whose brother is worthy of so much devotion! It
is pleasant to know that William Herschel deserved the love so lavishly
poured out at his feet; that great as were his achievements in science,
lofty and broad as was his genius, they were fully sustained and
ennobled by the beauty and worth of his inner life. Who can contemplate
their twofold career in all its singleness of purpose, its purity, its
unselfishness, its sublime disregard of worldly pleasures, without
emotion? The lessons told by such a life are worth all the moral
treatises ever written.
To Miss Herschel's diary we again refer, for a glimpse of the
occupations of her brother and herself at Slough in the first two years
of their residence. These two years, to use an apt expression of her
own, were spent in a perfect chaos of business. The garden and workrooms
swarmed with labourers and workmen--smiths and carpenters speeding to
and fro between the forge and the forty-foot machinery; and so incessant
was the vigilance of Herschel, that not a screw-bolt in the whole
apparatus was fixed except under his eye. "I have seen him," writes his
sister, "lying stretched many an hour in the burning sun, across the top
beam, whilst the iron-work for the various motions [of the great
telescope] was being fixed." At one time no fewer than twenty-four men,
in relays of twelve each, were engaged in grinding and polishing day and
night; and Herschel never left them, taking his food without allowing
himself time to sit down to table.
"In August 1787," writes the diarist, "an additional
man-servant was engaged, who would be wanted at the handles of
the motions of the forty-foot,"--that is, to raise or lower it,
or move it from side to side, as might be required,--"for which
the mirror in the beginning of July was so far finished as to
be used for occasional observations on trial. Such a person was
also necessary for showing the telescopes to the curious
strangers, as by their numerous visits my brother and myself
had for some time past been much incommoded. In consequence of
an application made through Sir J. Banks to the king, my
brother had in August a second sum of £2000 granted for
completing the forty-foot, and £200 yearly for the expense of
repairs; such as ropes, painting, &c., and the keep and
clothing of the men who attended at night. A salary of £50 a
year was also settled on me, as an assistant to my brother. A
great uneasiness was by this means removed from my mind; for
though I had generally (and especially during the last busy six
years) been almost the keeper of my brother's purse, with a
charge to provide for my personal wants, only annexing in my
accounts the memorandum '_For Car_.' to the sums so laid out.
When cast up, they hardly amounted to seven or eight pounds per
year since the time we had left Bath. Nothing but bankruptcy
had all the while been running through my silly head, when
looking at the sums of my weekly accounts, and knowing they
could be but trifling in comparison with what had been and had
yet to be paid in town. I will only add, that from this time
the utmost activity prevailed to forward the completion of the
forty-foot."
In recognition of his scientific triumphs, the honorary degree of LL.D
was conferred upon Herschel, in 1786, by the University of Oxford. They
were triumphs that well merited such a recognition. He had already made
some important observations on the nature of double stars, on the
dimensions of the telescopic planets, and had begun his famous
investigations into the composition of the nebulae,--those clusters of
stars and nebulous matter which had previously proved such a problem to
astronomers. The remarkable phenomenon of a periodical change of
intensity in certain stars, which wax and wane in radiance like a
revolving light, had also excited his attention. Further, he had entered
upon the experiments which ultimately showed that the Sun positively
moves; that in this, as in other respects, the magnificent orb of day
must be ranged among the stars; that the apparently inextricable
irregularities of numerous sidereal proper motions arise in great part
from the displacement of the Solar System; that, in short, the point of
space toward which Earth and its sister planets are annually advancing,
is situated in the constellation of Hercules.
"Let us," says a French writer, "to these immortal labours add the
ingenious ideas that we owe to Herschel on the nebulae, on the
constitution of the Milky Way, on the Universe as a whole,--ideas which
almost by themselves constitute the actual history of the formation of
the worlds,--and we cannot but have a deep reverence for that powerful
genius that scarcely ever erred, notwithstanding the ardour of its
imagination."
The ordinary spectator, looking upon the face of the heavens through a
telescope, had, prior to Herschel's time, felt his curiosity excited by
the appearance here and there of filmy patches, vague in structure and
irregular in shape, which, from their resemblance to clouds, received
the name of _nebulae_. What these were, no astronomer had succeeded in
defining. It was left for Herschel, with his rare powers of patient and
discriminating observation, assisted by the more powerful instruments
which his ingenuity succeeded in constructing, to discern in them
innumerable groups of worlds, in various stages of formation! A new
light was thrown upon the history of the Universe. Man was able to
assist, as it were, at the process of creation, and to watch the
development of a mass of incoherent matter into a perfect star. This
alone was a discovery which might well have immortalised the name of
Herschel.
But we owe to him the elements of our knowledge of the Sun's physical
constitution. He swept aside the erroneous theories and conjectures
which had previously prevailed, and guided the astronomical inquirer
into the right path. He convinced himself, by long and patient
researches, that the luminous envelope of the great "orb of day" was
neither a liquid nor an elastic fluid; that it was in certain respects
analogous to the clouds which wreathe our mountain-summits and fertilize
our plains; that it floated in the solar atmosphere. Thence he came to
the conclusion that the Sun has two atmospheres, endowed with motions
quite independent of each other. An elastic fluid, now known as the
_photosphere_, is in course of continual formation on the dark rugged
surface of the solar mass; and rising, on account of its specific
lightness, it forms the _pores_ in the stratum of reflecting clouds;
then, combining with other gases, it produces the irregularities or
furrows in the luminous cloud-region. When the ascending currents are
powerful, they create those appearances which astronomers designate the
_nuclei_, the _penumbrae_, the _faculae_.
Such was Herschel's explanation of the mode of formation of the solar
spots; and allowing it to be well-founded, we must expect to find--what
is, indeed, the case--that the Sun does not always and regularly pour
forth equal quantities of light and heat. It is true that Herschel's
hypothesis has been modified by later astronomers; but his is the credit
of having directed them into the right course of inquiry and
observation.
* * * * *
The physical constitution of the Moon was a subject which also engaged
the attention of our indefatigable enthusiast. As early as 1780 he
attempted the measurement of the lunar mountains, and came to the
conclusion that few of them exceeded 2600 feet in height. Later
research, however, has proved these figures to be inadequate. Next he
addressed himself to a study of the lunar volcanoes, three of which he
declared to be in a state of ignition; two of them apparently on the
decline, the third still active. He was so convinced of the reality of
the phenomenon, that on the 20th of April 1787 he wrote:--"The volcano
burns with greater violence than it did last night." The real diameter
of the volcanic light he estimated at 16,400 feet. Its intensity he
described as superior to that of the nucleus of a comet then flashing
across our system. The objects situated near the crater were fully
illuminated by the glare of its burning matter.
It may seem strange that, after observations so exact and minute, few
astronomers now admit the existence of active volcanoes in the Moon. The
reasons for their incredulity are thus stated:--
The various parts of the Moon do not all reflect with the same
intensity. Here, that intensity may be dependent on the form;
elsewhere, on the nature of the materials. Those persons who have
examined the lunar orb with telescopes, know how very considerable the
difference arising from these two causes may be,--with how much keener
and stronger a radiance one point of the Moon will sometimes shine than
those around it. Well, it would seem to be obvious that the ratio of
intensity between the brilliant parts and the faint parts must always be
the same, whatever the origin of the illuminating light. In that portion
of the lunar sphere which receives the glow and glory of the sun, we
know that some points exist, the brightness of which is extraordinary
compared with the feeble flickering gleam of those around them. And
these same points, when seen in the dim reflection of the Earth, will
still predominate in intensity over the neighbouring regions. In this
way Arago and others explain the observations of Herschel, without
admitting the existence of active volcanoes in the Moon. That volcanoes
there are, is a familiar fact; but they would seem to have exhausted
their activity in long-past ages. The lunar surface is now a dreary
waste of rugged lava and ashes, covered with the matter ejected from
craters once in a state of furious eruption. The Moon, in fact, is a
world which has burned itself out. How strange the thought that in a
far-back period the inhabitants of Earth, had Earth then been inhabited,
might have seen the glare of countless volcanoes diffused, lurid and
threatening, over the face of their satellite! How strange the thought
that the once active fires should all have died away, and the Moon have
thus been prepared for the better reception and reflection of the solar
radiance in order to illuminate the nights of Earth!
The planets, needless to say, were the objects of Herschel's assiduous
attention. Mercury was the one which least interested him; but he
ascertained the perfect circularity of its disc. With respect to Venus,
he endeavoured to determine the time of its rotation from 1777. We owe
to him the discovery of the true shape of the "red planet Mars,"--that,
like the Earth, it is an oblate spheroid, or flattened at the poles.
After Piazzi, Olbers, and Harding had discovered the small planets,
Ceres, Pallas, Juno, and Vesta, he applied himself to the measurement
of their angular diameters. His researches led him to the conclusion
that these four new bodies could not properly be ranked with the
planets, and he proposed to call them Asteroids--a name now generally
adopted. Since Herschel's time, the number of these minor planets known
to astronomers has increased to upwards of one hundred.
With respect to Jupiter, our astronomer arrived at some important facts
in connection with the duration of its rotation. He also made numerous
observations on the intensities and comparative magnitudes of its
satellites.
We come next in order to Saturn, the gloomy planet which the ancient
astrologers regarded with so much dislike. Here, too, we find traces
of Herschel's labours. Not only has he enlarged our knowledge of its
equatorial compression, of its physical constitution, and of the
rotation of its luminous belt or ring, but he added two to the number
of its satellites. Five only of these were known at the close of the
seventeenth century; of which Cussiric discovered four, and Huygens one.
It was universally believed that the subject was exhausted.
But, on the 28th of August 1780, Herschel's colossal tube revealed to
his delighted gaze a satellite nearer to the Saturnian ring than those
previously observed. And a few days later, on the 17th of September, a
seventh and last satellite crossed his field of vision. It was situated
between the former and the ring; that is, it is the nearest to it of the
seven.
But the most remarkable of Herschel's achievements was the discovery of
the planet Uranus, and the detection of its satellites.
On the 13th of March 1781, between ten and eleven o'clock at night, the
great astronomer was engaged in examining the small stars near H in the
constellation Gemini, with a seven-foot telescope, bearing a magnifying
power of two hundred and twenty-seven times. It appeared to him that
one of these stars was of an unusual diameter; and he came to the
conclusion, therefore, that it was a comet. It was under this
denomination that it was discussed at the meeting of the Royal Society.
But the researches of Herschel at a later period showed that the orbit
of the new body was circular, and accordingly it was elevated to the
rank of a planet. As already stated, Herschel named it, in compliment to
George III., the Georgium Sidus; in this copying the example of Galileo
with his "Medicaean stars." Afterwards, astronomers christened it
Herschel, and subsequently Uranus, in conformity with the mythological
nomenclature of the other planets.
The immense distance of Uranus from our Earth, its small angular
diameter, and the feebleness of its light, seemed to preclude the hope
that, if it were attended by satellites of the same dimensions in
proportion to its own magnitude as those of the satellites of Jupiter
and Saturn in proportion to _their_ magnitude, they could be descried by
any human observer. The patient, persevering, reverent temper of
Herschel took no account, however, of any discouraging or unpropitious
circumstances. What he did was to substitute for telescopes of the
ordinary construction the new and gigantic forty-foot tube already
described; and, thus, with unremitting vigilance and intense zeal, he
arrived at the discovery (between January 4, 1787, and February 28,
1794) of the _six_ satellites of Uranus; in other words, he revealed to
man the completeness of a new system,--a system which will always be
identified with his name.
* * * * *
Those singular meteors, the comets, which flash through heaven with long
trails of light, and of old astonished the nations as if they were
harbingers of some overwhelming calamity, were also the frequent
subjects of our astronomer's investigations. He brought some of his fine
and powerful instruments to bear on a comet discovered by Mr. Pigott in
1807, and closely and carefully investigated its physical constitution.
The nucleus, or head, was circular and well determined, and evidently
shone by its own light. Very small stars seemed to grow pale, "to hide
their diminished heads," when seen through its _coma_ or tail. It is
true, however, that this faintness may have been only apparent, and due
to the circumstance of the stars being projected on a luminous
background. Such was Herschel's explanation. A gaseous medium, capable
of absorbing sufficient solar radiance to efface the light of some
"lesser stars," appeared to him to possess in each stratum a sensible
quantity of matter. Hence it would cause a real diminution of the light
transmitted, though nothing would indicate the existence of such a
cause.[1]
[Footnote 1: This conclusion is disputed by many astronomers.]
Herschel examined the beautiful comet of 1811 with equal accuracy.
"Large telescopes showed him, in the midst of the gaseous head, a rather
reddish body of planetary appearance, which bore strong magnifying
powers, and showed no sign of _phase_ (that is, of change of aspect, as
in the case of the Moon). Hence Herschel concluded that it was
self-luminous. Yet, if we reflect that the planetary body under
consideration was not a second in diameter, the absence of a phase,"
says Arago, "does not appear a demonstrative argument."
The same writer adds:--
"The light of the head had a bluish-green tint." Was this a
real tint, or did the central reddish body, only through
contrast, make the surrounding vapour appear to be coloured?
Herschel did not examine the question from this point of view.
"The head of the comet appeared to be enveloped at a certain
distance, on the side towards the Sun, by a brilliant narrow
zone, embracing about a semicircle, and of a yellowish colour.
From the two extremities of the semicircle arose, towards the
region away from the Sun, two long luminous streaks which
limited the tail. Between the brilliant circular semi-ring and
the head, the cometary substance appeared to be dark, of great
rarity, and very diaphanous.
"The luminous self-ring floated: one day it seemed to be
suspended in the diaphanous atmosphere by which the head of the
comet was surrounded, at a distance of 322,000 English miles
from the nucleus.
"This distance was not constant. The matter of the semi-annular
envelope seemed even to be precipitated by slow degrees through
the diaphanous atmosphere; finally, it reached the nucleus; the
earlier appearances vanished; the comet was reduced to a
globular nebula.
"During its period of dissolution, the ring appeared sometimes
to have several branches.
"The luminous shreds of the tail apparently underwent rapid,
frequent, and considerable variations of length. Herschel
discerned symptoms of a rotatory movement both in the comet and
its tail; a movement which carried unequal shreds from the
centre towards the border, and the border towards the centre.
On examining at intervals the same region of the tail--the
border, for example--sensible changes of length must have been
perceptible; which, however, had no reality in them. Herschel
thought that both the comet of 1811 and that of 1807 were
self-luminous. The second comet of 1811 appeared to him to
shine only by borrowed light. It must be acknowledged that
these conjectures did not rest on anything demonstrative.
"In attentively comparing the comet of 1807 with the beautiful
comet of 1811, relative to the changes of distance from the
Sun, and the modifications resulting thence, Herschel put it
beyond doubt that these modifications have something individual
in them,--something relative to a special state of the nebulous
matter. On one celestial body the changes of distance produce
an enormous effect, on another the modifications are
insignificant."
We have reproduced these observations by a distinguished French
astronomer, in order to show the reader what was the nature, and how
great was the importance, of Herschel's labours, and in how remarkable
and comprehensive a manner he conducted his survey of the celestial
phenomena. We now return to our brief narrative of his life.
Such a life, absorbed in tranquil and incessant studies, presents no
curious, romantic, or surprising incidents. It was the life of a
reverent, patient, gentle, and devoted man of genius, who dedicated
himself to the task of making known the "wondrous works of God" to his
fellow-men, and who in all his social and domestic relations was without
blot or stain.
In 1788 he married the widow of John Pitt, Esq., with whom he received
a considerable fortune, and thus for the remainder of his life he was
enabled to give himself up to his favourite pursuits unembarrassed by
pecuniary anxieties. His marriage was in every respect a happy one, and
effectually secured his domestic peace. By his wife he had an only
son,--the late Sir John Herschel,--who worthily maintained the
scientific dignity of his name.
It is said, by the highest of all authority, that a prophet is not
honoured in his own country. But our astronomer was not without the
reward of his work, even in his lifetime. The University of Oxford
conferred upon him the illustrious honorary degree of D.C.L. In 1816 he
received the Guelphic order of knighthood; and in 1820 he was chosen the
first president of the Astronomical Society.
From his sister's diary we gather a few particulars illustrative of his
mode of life.
On the 4th of October 1806 she writes:--
"My brother came from Brighton. The same night two parties from
the castle [Windsor] came to see the comet, and during the
whole month my brother had not an evening to himself. As he was
then in the midst of polishing the forty-foot mirror, rest
became absolutely necessary after a day spent in that most
laborious work; and it has ever been my opinion, that on the
14th of October his nerves received a shock of which he never
got the better afterwards; for on that day (in particular) he
had hardly dismissed his troop of men, when visitors assembled,
and from the time it was dark till past midnight he was on the
grass-plot, surrounded by between fifty and sixty persons,
without having had time for putting on proper clothing, or for
the least nourishment passing his lips.
"_February 6th, 1807_.--When I came to Slough to assist my
brother in polishing the forty-foot mirror, I found my
nephew[1] very ill with an inflammatory sore throat and fever.
"_February 9th_.--Still very ill; and my brother obliged to go
on with the polishing of the great mirror, as every arrangement
had been made for that purpose.--_Mem_. I believe my brother
had reasons for choosing the cold season for this laborious
work, the exertion of which alone must put any man into a
fever, if he were ever so strong.
"_February 10th_.--From this day my nephew's health kept on
mending.
"_February 19th_.--My nephew mending, but my brother not well.
"_February 26th_.--My brother so ill that I was not allowed to
see him, and till March 8th his life was despaired of; and by
March 10th I was permitted to see him, but only for two or
three minutes, as he was not allowed to speak.
"_March 22nd_.--He (Sir William) went for the first time into
his library, but could only remain for a few moments."
[Footnote 1: Afterwards Sir John Herschel.]
From this dangerous attack Sir William recovered, but thenceforth it
was clear to his friends that his strength gradually decreased, though
not his enthusiasm or his industry. He persevered in his life-long
labours with all his old intellectual force. What failed him was neither
his tender affections nor his mental powers; but his body refused to
answer all the demands made upon it by the resolute will,--the sword was
slowly but surely wearing out the scabbard. Under the date of April 2,
1819, we meet with an ominous entry in his loving and faithful sister's
diary:--
"My brother left Slough, accompanied by Lady Herschel, for
Bath, he being very unwell; and the constant complaint of
giddiness in the head so much increased, that they were obliged
to be four nights on the road both going and coming. The last
moments before he stepped into the carriage were spent in
walking with me through his library and workrooms, pointing
with anxious looks to every shelf and drawer, desiring me to
examine all, and to make memorandums of them as well as I
could. He was hardly able to support himself; and his spirits
were so low, that I found difficulty in commanding my voice so
far as to give him the assurance he should find on his return
that my time had not been misspent.
"When I was left alone, I found that I had no easy task to
perform, for there were packets of writings to be examined
which had not been looked at for the last forty years. But I
did not pass a single day without working in the library as
long as I could read a letter without candlelight, and taking
with me papers to copy, which employed me for best part of the
night; and thus I was enabled to give my brother a clear
account of what had been done at his return. But (May 1) he
returned home much worse than he went, and for several days
hardly noticed my handiwork."
To this same year of decay and decline (1819) belongs a small slip of
yellow paper, inscribed with the following lines in a tremulous and
feeble handwriting, which is jealously preserved by the illustrious
astronomer's descendants:--
"LINA,--There is a great comet. I want you to assist me. Come
to dine, and spend the day here. If you can come soon after one
o'clock, we shall have time to prepare maps and telescopes. I
saw its situation last night,--it has a long tail.
"_July 4, 1819_."
Then follows:--
"I keep this as a relic! Every line _now_ traced by the hand of
my dear brother becomes a treasure to me.
"C. HERSCHEL."
We know of nothing more touching in literary history than this noble,
self-sacrificing, generous affection of the sister towards her eminent
brother. Such instances of absolute self-denial and all-absorbing love
elevate our opinion of human nature generally, and prove that something
of the Divine image lingers in it still.
Herschel was now bordering upon the ripe old age of eighty, and it is no
wonder that, after a life of incessant study, his strength should daily
diminish. In 1822 it became painfully evident to his attached relatives
and friends that the end was not far off; and on the 25th of August he
passed away to his rest. We owe an account of his last days to his
sister, but for whose pious care, indeed, very little of his private
life would have been known, and Herschel could have been judged only
from the recorded results of his immense labours.
"_May 20th_.--The summer proved very hot; my brother's feeble
nerves were very much affected, and there being in general much
company, added to the difficulty of choosing the most airy
rooms for his retirement.
"_July 8th_.--I had a dawn of hope that my brother might regain
once more a little strength, for I have a memorandum in my
almanac of his walking with a firmer step than usual above
three or four times the distance from the dwelling-house to the
library, in order to gather and eat raspberries, in his garden,
with me. But I never saw the like again.
"The latter end of July I was seized by a bilious fever, and I
could for several days only rise for a few hours to go to my
brother about the time he was used to see me. But one day I was
entirely confined to my bed, which alarmed Lady Herschel and
the family _on my brother's account_. Miss Baldwin [a niece of
Lady Herschel] called and found me in despair about my own
confused affairs, which I never had had time to bring into any
order. The next day she brought my nephew to me, who promised
to fulfil all my wishes which I should have expressed on paper;
he begged me not to exert myself, for his father's sake, of
whom he believed _it would be the immediate death if anything
should happen to me_."
Afterwards she wrote:--
"Of my dear nephew's advice I could not avail myself, for I
knew that at that time he had weighty concerns on his mind.
And, besides, my whole life almost has passed away in the
delusion that, next to my eldest brother, none but Dietrich was
capable of giving me advice where to leave my few relics,
consisting of a few books and my sweeper [that is, the
seven-foot telescope with which she was accustomed to sweep the
heavens for comets]. And for the last twenty years I kept to
the resolution of never opening my lips to my dear brother
William about worldly concerns, let me be ever so much at a
loss for knowing right from wrong."
Miss Herschel proceeds to note that on the afternoons of the 11th, 12th,
13th, and 14th of August, she, "as usual," spent some hours with her
brother.
On the 15th she hastened to the accustomed place, where she generally
found him, with the newspaper which she was to read aloud for his
amusement. But, instead, she found assembled there several of his
nearest friends, who informed her that her aged brother had been
compelled to return to his room. She lost no time in seeking him. He was
attended by Lady Herschel and his housekeeper, who were administering
everything which was likely to keep up his failing strength.
Miss Herschel observed that he was much irritated, with the irritation
natural to old age and extreme bodily feebleness, at his inability to
grant a friend's request for some token of remembrance for his father.
No sooner did he see Miss Herschel, the loving companion and
fellow-worker of so many years, than he characteristically employed her
to fetch one of his last papers, and a plate (or map) of the forty-foot
telescope. "But, for the universe," says Miss Herschel, "I could not
have looked twice at what I had snatched from the shelf; and when he
faintly asked if the breaking up of the Milky Way[1] was in it, I said,
'Yes,' and he looked content." I cannot help remembering this
circumstance; it was the last time I was sent to the library on such an
occasion. That the anxious care for his papers and workrooms never ended
but with his life, was proved by his frequent whispered inquiries if
they were locked and the key safe; of which I took care to assure him
that they were, and the key in Lady Herschel's hands.
[Footnote 1: The _Via Lactea_, or "Milky Way," had long been supposed to
consist of a nebulous, vague, luminous matter, but Herschel showed that
it was really made up of stars and systems of stars.]
After struggling for some thirty minutes against his rapidly increasing
weakness, the great astronomer, bowed by his burden of years and
labours, was forced to retire to his bed, with little hope that he would
ever rise from it again. For ten days and nights his wife and sister
watched by his side in painful suspense, until, on the 25th of August,
the end came. Peacefully closed a life which had passed in a peace and
quietness not often vouchsafed to man.
* * * * *
Herschel, says a brother astronomer, will never cease to occupy an
eminent place in the small group of our contemporary men of genius,
while his name will descend to the most distant posterity. The variety
and the magnificence of his labours vie with their extent. The more they
are studied, the more they are admired. For it is with great men as it
is with great movements in the Arts and in national history,--we cannot
understand them without observing them from different points of view.
What a brilliant roll of achievements is recalled to the mind by the
name of William Herschel! The discovery of Uranus, and of its
satellites; of the fifth and sixth satellites of Saturn; of the many
spots at the poles of Mars; of the rotation of Saturn's ring; of the
belts of Saturn; of the rotation of Jupiter's satellites; of the daily
period of Saturn and Venus; and of the motions of binary sidereal
systems,--added to his investigations into nebulae, the Milky Way, and
double, triple, and multiple stars;--all this we owe to his patient, his
persevering, his daring genius! He may almost be styled the Father of
Modern Astronomy.