We now propose to furnish a brief sketch of the life of Sir John
Frederick William Herschel, the only son of Sir William, and not less
illustrious as a man of science.
He was born at Slough, in the year 1792. Evincing considerable talents
at a very early age, he received a careful private education under Mr.
Rogers, a Scottish mathematician of distinguished merit; and afterwards
was sent to St. John's College, Cambridge, always famous as a nursery of
mathematical and scientific prodigies! Here he pursued his studies with
remarkable success, suffering no obstacles to daunt him, and wasting no
opportunities of improvement. His fellow-collegians regarded him as one
who would add to the high repute of the college, and rejoiced at the
brilliant ease with which he passed every examination. In 1813 he took
his degree of B.A., and consummated a long series of successes by
becoming "senior wrangler," and "Smith's prizeman;" these being the two
highest distinctions to which a Cambridge scholar can attain.
In the same year, when he was hardly twenty-one, he published a work
entitled, "A Collection of Examples of the Application of the Calculus
to Finite Differences." To our young readers such a title will convey no
meaning; and we refer to it here only to illustrate the industry and
careful thought of the young student, which had rendered possible such a
result.
Returning to Slough, he continued his studies in mathematics, chemistry,
and natural philosophy, and in various publications exhibited that
faculty of observation and analyzation, that intelligence and
scrupulousness in collecting facts, and that boldness in deducing new
inferences from them, which were characteristic of his illustrious
father. The subjects he took up were so abstruse, that we could not hope
to make our readers understand what he accomplished, or how far he
excelled his predecessors in his grasp and comprehension of them. For
instance: if we tell them that in 1820 he wrote a paper "On the Theory
and Summation of Series;" communicated to the Cambridge Philosophical
Society his discovery that the two kinds of rotatory polarization in
rock crystal were related to the plagihedral faces of that mineral; and
issued an able treatise "On Certain Remarkable Instances of Deviation
from Newton's Tints in the Polarized Tints of Uniaxal Crystals,"--they
will gain no very distinct idea of the significance or value of these
researches. Again: it will not be very intelligible to them to be
informed that, in 1822, he communicated to the Royal Society of
Edinburgh a paper "On the Absorption of Light by Coloured Media", in
which he enunciated a new method of measuring the dispersion of
transparent bodies by stopping the green, yellow, and most refrangible
red rays, and thus rendering visible the rays situated rigorously at the
end of the spectrum. But they will understand that these results could
have been attained only by the most assiduous industry and the most
unflinching perseverance. And it is on account of this industry and
this perseverance that we recommend Herschel as an example to our
readers. They may not make the same progress in science, or achieve the
same reputation. It is not necessary they should. Humble work is not
less honourable, if it be done conscientiously, and with a sincere
desire to do the best that it is in our power to do.
An interesting feature in the younger Herschel's character was his
loving care for his father's fame. He was ever most anxious that the
full measure of his services to science should be recognized and
appreciated. Thus, in 1823, he writes to his aunt:--
"I have been long threatening to send you a long letter, but
have always been prevented by circumstances and want of leisure
from executing my intention. The truth is, I have been so much
occupied with astronomy of late, that I have had little time
for anything else--the reduction of those double stars, and the
necessity it has put me under of looking over the journals,
reviews, &c, for information on what has already been done, and
in many cases of re-casting up my father's measures, swallows
up a great deal of time and labour. But I have the satisfaction
of being able to state that our results in most instances
confirm and establish my father's views in a remarkable manner.
These inquiries have taken me off the republication of his
printed papers for the present.
"I think I shall be adding more to his fame by pursuing and
verifying his observations than by reprinting them. But I have
by no means abandoned the idea. Meanwhile, I am not sorry to
hear they are about to be translated into German.... I hope
this season to commence a series of observations with the
twenty-foot reflector, which is now in fine order. The
forty-foot is no longer capable of being used, but I shall
suffer it to stand as a monument."
* * * * *
In reference to this famous telescope, we may digress to state that its
remains have been carefully preserved.
The metal tube of the instrument, carrying at one end the recently
cleaned mirror of four feet ten inches in diameter, has been placed
horizontally in the meridian line, on solid piles of masonry, in the
midst of the circle where the apparatus used in manoeuvring it was
formerly placed. On the 1st of January 1840, Sir John Herschel, his
wife, their seven children, and some old family servants, assembled at
Slough. Exactly at noon the party walked several times in procession
round the instrument; they then entered the gigantic tube, seated
themselves on benches previously prepared, and chanted a requiem with
English words composed by Sir John Herschel himself. Then issuing from
the tube, they ranged themselves around it, while its opening was
hermetically sealed.
* * * * *
In March 1821, the younger Herschel, in conjunction with Sir James
South, undertook a series of observations on the distances and positions
of three hundred and eighty double and triple stars, by means of two
splendid achromatic telescopes of five and seven focal length. These
were continued during 1822 and 1823, and have proved of great service to
astronomers.
Having pursued with much zeal the study of optics, and experimented
largely and carefully on the double refraction and polarization of
light, he compiled a treatise on the subject for the "Encyclopaedia
Metropolitana" It has been translated into French by M. Quetelet; and
both foreign and English men of science have been accustomed to regard
it as indicating a new point of departure in the important branch of
science to which it is devoted.
Astronomy, however, became for him, as for his father, the great
pursuit of his laborious life; and having constructed telescopes of
singular magnitude and power, he entered upon a study of the Sidereal
World. In 1825 he commenced a careful re-examination of the numerous
nebulae and starry clusters which had been discovered by his father, and
described in the "Philosophical Transactions," fixing their positions
and investigating their aspects. He devoted eight years to this _magnum
opus_, completing it in 1832. The catalogue which he then contributed to
the "Philosophical Transactions" includes 2306 nebulae and
star-clusters, of which 525 were discovered by himself. While engaged in
this difficult task, Herschel discovered between three and four thousand
double stars, which he described in the Memoirs of the Astronomical
Society. His observations were made with an excellent Newtonian
telescope, twenty feet in focal length, and eighteen and a half inches
in aperture; and having obtained, to use his own expression, "a
sufficient mastery over the instrument," the idea occurred to him of
making it available for a survey of the southern heavens. Accordingly,
he left England on the 13th of November 1833, and arrived at Cape Town
on the 16th of January 1834. Five days later he wrote to his aunt as
follows:--
"Here we are safely lauded and comfortably housed at the far
end of Africa; and having secured the landing and final storage
of all the telescopes and other matters, as far as I can see,
without the slightest injury, I lose no time in reporting to
you our good success _so far_. M----[1] and the children are,
thank God, quite well; though, for fear you should think her
too good a sailor, I ought to add that she continued sea-sick,
at intervals, during the whole passage. We were nine weeks and
two days at sea, during which period we experienced only one
day of contrary wind. We had a brisk breeze 'right aft' all the
way from the Bay of Biscay (which we never entered) to the
'calm latitudes;' that is to say, to the space about five or
six degrees broad near the equator, where the trade-winds
cease, and where it is no unusual thing for a ship to lie
becalmed for a month or six weeks, frying under a vertical sun.
Such, however, was not our fate. We were detained only three or
four days by the calms usual in that zone, but never _quite_
still, or driven out of our course; and immediately on crossing
'the line' got a good breeze (the south-east trade-wind), which
carried us round Trinidad; then exchanged it for a north-west
wind, which, with the exception of one day's squall from the
south-east, carried us straight into Table Bay. On the night of
the 14th we were told to prepare to see the Table Mountain.
Next morning (_N.B._, we had not seen land before since leaving
England), at dawn, the welcome word land' was heard; and there
stood this magnificent hill, with all its attendant
mountain-range down to the farthest point of South Africa, full
in view, with a clear blue ghost-like outline; and that night
we cast anchor within the Bay. Next morning early we landed,
under escort of Dr. Stewart, M----'s brother, and you may
imagine the meeting. We took up our quarters at a most
comfortable lodging-house (Miss Robe's), and I proceeded,
without loss of time, to unship the instruments. This was no
trifling operation, as they filled (with the rest of our
luggage) fifteen large boats; and, owing to the difficulty of
getting them up from the hold of the ship, required several
days to complete the landing. During the whole time (and indeed
up to this moment) not a single south-east gale, the summer
torment of this harbour, has occurred. This is a thing almost
unheard of here, and has indeed been most fortunate, since
otherwise it is not at all unlikely that some of the boats,
laden as they were to the water's edge, might have been lost,
and the whole business crippled.
[Footnote 1: Herschel married a Miss Stewart in February 1826.]
"For the last two or three days we have been looking at houses,
and have all but agreed for one--a most beautiful place within
four or five miles out of town, called 'The Grove.' In point of
situation it is a perfect paradise, in rich and magnificent
mountain-scenery, and sheltered from all winds, even the fierce
south-easter, by thick surrounding woods. I must reserve for my
next all description of the gorgeous display of flowers which
adorns this splendid country, as well as of the astonishing
brilliancy of the constellations, which the calm, clear nights
show off to great advantage."
Mr. Herschel settled at Feldhausen, about 142 feet above the sea, and in
long. 22° 46' 9".11 E., and lat. 33° 58' 26".59 S. Here he entered upon
his great series of observations of the southern heavens, which he
continued with unwearied ardour for a period of four years. The results
were afterwards published, at the cost of the Duke of Northumberland, in
a work entitled "Results of Astronomical Observations made in
1834-35-36-37-38, at the Cape of Good Hope." In this superb work, which
placed its author on an equality with the most brilliant and illustrious
astronomers, he defined and described 4015 of the nebulae and
star-groups in the southern hemisphere, and 2995 of the double stars;
besides entering into a variety of valuable particulars relative to
Halley's comet, the solar spots, the satellites of Saturn, and the
measurement of the apparent magnitude of stars.
On his return to England (in 1838) the astronomer received a noble
welcome. Honours poured in upon him. The Gold Medal of the Astronomical
Society was conferred upon him for a second time. William IV. had
previously distinguished him with the Hanoverian order of K.H.; but, on
the coronation of Queen Victoria, he received a baronetcy; and in 1839
the University of Oxford made him a D.C.L.
Continuing his career of scientific industry, he issued, in 1849, his
important and very valuable treatise entitled "Outlines of Astronomy."
In 1845, he was appointed President of the British Association; and in
1848, of the Royal Astronomical Society. To his other honours was added
that of Chevalier of the Prussian order, "Pour la Mérite," founded by
Frederick the Great, and bestowed at all times with a discrimination
which renders it a deeply-coveted distinction. Of the academies and
leading scientific institutions of the Continent and the United States,
he was also an honorary or corresponding member.
Besides his works on meteorology and physical geography, he published,
in 1867, an admirable little volume--"Familiar Lectures on Scientific
Subjects." In this he showed that he could write with as much ease and
intelligibility for the general public as for the higher order of
scientific inquirers. His style in this valuable manual of information
has a charm of its own, and entices the reader into the consideration of
subjects apparently abstruse. He is earned on from page to page without
any great mental effort, and finds himself rapidly mastering
difficulties which he had been accustomed to regard as insuperable.
Let us take the first lecture on "Volcanoes and Earthquakes," and obtain
a glimpse of Herschel's mode of treatment. He refers to the greater and
more permanent agencies which affect the configuration of our planet.
Everywhere, he says, and along every coast-line, we see the sea warring
against the land, and overcoming it; wearing it and eating it down, and
battering it to pieces; grinding those pieces to powder; carrying that
powder away, and spreading it out over its own bottom, by the continued
effect of the tides and currents. What a scene of continual activity is
presented by the chalk-cliffs of Old England! How they are worn, and
broken up, and fantastically sculptured by the influence of winds and
waters! Precipices cut down to the sea-beach, constantly hammered by the
waves, and constantly crumbling; the beach itself made of the flints
outstanding after the softer chalk has been ground down and washed
away; themselves grinding one another under the same ceaseless
discipline--first rounded into pebbles, then worn into sand, and then
carried further and further down the slope, to be replaced by fresh ones
from the same source. Here the likeness of an old Gothic cathedral, with
lofty arch, and shapely pinnacle; there the similitude of a mass of
medieval fortifications, with crumbling battlements and shattered
towers!
The same thing, the same waste and wear, is going on everywhere, round
every coast. The rivers contribute their share to the great work of
change. Look at the sand-banks at the mouth of the Thames. What are
they, says Sir John Herschel, but the materials of our island carried
out to sea by the stream? The Ganges carries away from the soil of
India, and delivers into the sea, twice as much solid substance weekly
as is contained in the Great Pyramid of Egypt. The Irawaddy sweeps off
from Burmah sixty-two cubic feet of earth in every second of time, on an
average Sometimes vast amount of earthy materials is transferred from
one locality to another by river agency, as is the case in the deltas
of the Nile and the Mississippi.
These changes operate silently, continuously, and unperceived by the
ordinary observer; but Nature does not limit herself always and
everywhere to such peaceful agencies. At times, and in certain places,
she acts with startling abruptness and extraordinary violence. Let the
volcano and the earthquake attest the immensity of her power. Let the
earthquake tell how, within the memory of man, the whole coast-line of
Chili, for 100 miles about Valparaiso, with the mighty chain of the
Andes, was hoisted at one blow, and in a single night (November 19,
1822), from two to seven feet above its former level, leaving the beach
below the old low-water mark high and dry. One of the Andean peaks
upheaved on this occasion was the colossal mass of Aconcagua, which
overlooks Valparaiso, and measures nearly 24,000 feet in height. On the
same occasion, at least 10,000 square miles of country were estimated as
having been upheaved; and the upheaval was not confined to the land, but
extended far away to sea,--which was proved by the soundings off
Valparaiso and along the coast having been found considerably shallower
than they were before the shock.
In the year 1819, in an earthquake in India, in the district of Cutch,
bordering on the Indus, a tract of country more than fifty miles long
and sixteen miles broad was suddenly raised _ten feet_ above its former
level. The raised portion still stands up above the unraised, like a
long perpendicular rampart, known by the name of Ullah Bund, or God's
Wall.
* * * * *
With a similar fertility of illustration, Herschel sets before us the
phenomena of volcanic eruptions and their extraordinary effects.
In a district of Mexico, between the two streams of the Cintimba and the
San Pedro, on the 28th of September 1789, a whole tract of ground, from
three to four miles in extent, surged up like a foam-bubble, or the
swell of a wave, to a height of upwards of 500 feet. Flames, lurid and
crackling, broke forth over a surface of more than half a square league;
and the earth, as if softened by heat, was seen to rise and sink like
the rolling tide. Vast chasms opened in the earth, into which the two
rivers poured their waters headlong; reappearing afterwards at no great
distance from a cluster of _hornitos_, or small volcanic cones, which
sprang out of the mighty mud-torrent that gradually covered the entire
plain. Wonderful and awful as were these phenomena, they were surpassed
by the sudden opening of a chasm which vomited forth fire, and red-hot
stones and ashes, until they accumulated in a range of six large
mountain masses,--one of which, now known as the volcano of Jorullo,
attains an altitude of 1690 feet above the ancient level.
In like manner Sir John proceeds to describe an eruption of Mount
Tomboro, in the island of Sumbawa, the influence of which was felt to a
distance of 1000 miles from its centre, in strange tremulous motions of
the earth, and in the clash and clang of loud explosions. He says that
he had seen it computed that the quantity of ashes and lava ejected in
the course of this tremendous eruption would have formed three mountains
of the size of Mont Blanc.
As to the nature of the forces which operate to produce this astounding
result, Herschel puts forward a theory of singular simplicity and
directness.
"The origin," he says, "of such an enormous power thus occasionally
exerting itself, will no doubt seem very marvellous--little short,
indeed, of miraculous intervention; but the mystery, after all, is not
quite so great as at first it seems. We are permitted to look a little
way into these great secrets of Nature; not far enough, indeed, to clear
up every difficulty, but quite enough to penetrate us with admiration of
that wonderful system of counterbalances and compensations, that
adjustment of causes and consequences, by which, throughout all nature,
evils are made to work their own cure, life to spring out of death, and
renovation to tread in the steps and efface the vestiges of decay." And
he finds the clew to the secret, the key of the whole matter, in the
earth's vast central heat. This it is which produces the convulsions
that change the terrestrial configuration, and fill the minds of men
with fear and awe. Conceive of "a sea of fire, on which we are all
floating, land and sea,"--a boiling, seething, incandescent reservoir in
the centre of our planet; and the solution of the problem will seem to
you not difficult. Such a sea would necessarily roll its liquid matter
to and fro; and the removal of ever so small a portion from one point to
another on the earth's surface would tend to disturb the equilibrium of
the floating mass; just as, when a ship is launched into the river, the
water it displaces is carried to the opposite bank with greater or less
violence, according to the amount of displacement.
It is impossible, adds Herschel, but that this increase of pressure in
some places and relief in others must be very unequal in their bearings.
So that at some point or another our planet's floating crust must be
brought into a state of strain, and if there be a weak or a soft part a
crack will at last take place. This is exactly what happened in the
earthquake which originated the Allah Bund, or God's Wall, in Cutch.
Volcanic eruptions are easily explicable on this principle,--the volcano
being simply a vent for the passage of heated and molten matter, which
the elevating pressure of the liquid below tends to eject. It is a
well-known fact that volcanoes and earthquake-centres are nearly all
situated on the borders or in the immediate neighbourhood of seas and
oceans; and the reason would seem to be, that at such positions the
accumulation of transported matter would necessarily attain its maximum,
to whatever cause it might be due. Then again, as Herschel points out,
the eruption of scorite and lava from the mouths of volcanoes, the
result of the upward movement of the fiery liquid below, compensates in
some degree for the downward transfer of material by detritus and
alluvial deposits. Hence it may be inferred that, on the whole, the
quantity of solid matter above the ocean-level probably remains nearly
always at the same amount.
* * * * *
It is with this ease and lucidity that Sir John deals with scientific
subjects of the greatest importance,--his genius resembling the
elephant's trunk, which can balance a straw or rend an oak. In private
life he displayed a simplicity of manner in harmony with the general
unassumingness of his character. In his books as in society, in society
as in his books, he was the same,--that is, free from all ostentation,
free from self-pride, free from the arrogance of superior knowledge, and
as ready to unbend himself to a child as to discourse with men of
science.
His career was a tranquil and a prosperous one, and, apart from the
record of his discoveries and his honours, presents nothing of interest.
He was peculiarly happy in his domestic relations; and in the wide
circle of friends attracted by the mingled charm of his intellect and
manners. A devout Christian, a man of generosity and culture, a
philosopher of great breadth of view and infinite patience of
research,--we can place few better or brighter examples before our
English youth than Sir John Herschel.