the creation of the heavenly bodies to note how the biblical account
differs from it, not only or chiefly in details, but in general
character, we seem to recognize in the latter a determination to
detach from the celestial orbs the individuality, so to speak, which
the older tradition had given to them. The account in Genesis is not
only simpler, and, in a literary sense, more effective, but it is in
another sense purified. The celestial bodies do not appear in it as
celestial beings. The Babylonian legend is followed only so far as it
can be followed consistently with the avoidance of all that might tempt
to the worship of the sun, moon, and stars. The writer of the book of
Genesis, whether Moses or not, seems certainly to have shared the views
of Moses as to the Sabæanism of the nation from which the children
of Abraham had separated. Moses warned the Israelite,—“Take good
heed unto thyself, lest thou lift up thine eyes unto heaven; and when
thou seest the sun, and the moon, and the stars, even all the host of
heaven, shouldest be driven to worship them, and serve them, which the
Lord thy God hath divided unto all nations under the whole heaven.” So
the writer of Genesis is careful to remove from the tradition which he
follows all that might suggest the individual power and influence of
the heavenly bodies. The stars are to be for signs, but we read nothing
of the power of the wandering stars “to do injury or trouble any one.”
(That is, not in the book of Genesis. In the song of Deborah we find,
though perhaps only in a poetic fashion, the old influences assigned
to the planets, when the singer says that the “stars in their courses
fought against Sisera.” Deborah, however, was a woman, and women have
always been loth and late to give up ancient superstitions.) Again, the
sun and the moon in Genesis are the greater and the lesser lights, not,
as in the Babylonian narrative, the god Shamas and the god Uru.
We may find a parallel to this treatment of the Babylonian myth in the
treatment by Moses of the observance of the Sabbath, a day of rest
which the Babylonian tablets show to have had, as for other reasons
had been before suspected, an astrological significance. The Jewish
lawgiver does not do away with the observance; in fact, he was probably
powerless to do away with it. At any rate, he suffers the observance
to remain, precisely as the writer of the book of Genesis retains the
Babylonian tradition of the creation of the celestial bodies. But he
is careful to expurgate the Chaldæan observance, just as the writer
of Genesis is careful to expurgate the Babylonian tradition. The week
as a period is no longer associated with astrological superstitions,
nor the Sabbath rest enjoined as a fetish. Both ideas are directly
associated with the monotheistic principle which primarily led to the
separation of the family of Abraham from the rest of the Chaldæan race.
In Babylonia, the method of associating the names of the sun, moon,
and stars with the days, doubtless had its origin. Saturn was the
Sabbath star, as it is still called (Sabbatai) in the Talmud. But, as
Professor Tischendorf told Humboldt, in answer to a question specially
addressed to him on the subject, “there is an entire absence in both
the Old and New Testaments, of any traces of names of week-days taken
from the planets.” The lunar festivals, again, though unquestionably
Sabaistic in their origin, were apparently too thoroughly established
to be discarded by Moses; nay, he was even obliged to permit the
continuance of many observances which suspiciously resembled the old
offerings of sacrifice to the moon as a deity. He had also to continue
the sacrifice of the passover, the origin of which was unmistakably
astronomical,—corresponding in time to the sun’s passage across the
equator, or rather to the first lunar month following and including
that event. But he carefully dissociates both the lunar and the
lunisolar sacrifices from their primary Sabaistic significance. In
fact, the history of early Hebrew legislation, so far as it related to
religion, is the history of a struggle on the part of the lawgivers and
the leaders of opinion against the tendency of the people to revert to
the idolatrous worship of their ancestors and of races closely akin to
them—especially against the tendency to the worship of the sun and
moon and all the host of heaven.
In the very fact, however, that this contest was maintained, while yet
the Hebrew cosmogony, and in particular the Hebrew astrogony, contains
indubitable evidence of its origin in the poetical myths of older
Babylonia, we find one of the strongest proofs of the influence which
the literature of Babylon, when at the fulness of its development,
exerted upon surrounding nations. This influence is not more clearly
shown even by the fact that nearly 2000 years after the decay of
Babylonian literature, science, and art, a nation like the Assyrians,
engaged in establishing empire rather than in literary and scientific
pursuits, should have been at the pains to obtain copies of many
thousands of the tablet records which formed the libraries of older
Babylonia. In both circumstances we find good reason for hoping that
careful search among Assyrian and Babylonian ruins may not only be
rewarded by the discovery of many other portions of the later Assyrian
library (which was also in some sense a museum), but that other and
earlier copies of the original Babylonian records may be obtained.
For it seems unlikely that works so valuable as to be thought worth
recopying after 1500 or 2000 years, in Assyria, had not been more than
once copied during the interval in Babylonia. “Search in Babylonia,”
says Mr. Smith, “would no doubt yield earlier copies of all these
works, but that search has not yet been instituted, and for the present
we have to be contented with our Assyrian copies. Looking, however, at
the world-wide interest of the subjects, and at the important evidence
which perfect copies of these works would undoubtedly give, there can
be no doubt,” Mr. Smith adds, “that the subject of further search and
discovery will not slumber, and that all as yet known will one day be
superseded by newer texts and fuller and more perfect light.”
Printed by BALLANTYNE, HANSON & CO.
Edinburgh & London
FOOTNOTES
[1] More strictly, it plays the same part as a glass screen before a
glowing fire. When the heat of the fire falls on such a screen (through
which light passes readily enough), it is received by the glass,
warming the glass up to a certain point, and the warmed glass emits in
all directions the heat so received; thus scattering over a large space
the rays which, but for the glass, would have fallen directly upon the
objects which the screen is intended to protect.
[2] The case here imagined is not entirely hypothetical. We examine
Mercury and Venus very nearly under the conditions here imagined; for
we can obtain only spectroscopic evidence respecting the existence
of water on either planet. In the case of Mars we have telescopic
evidence, and no one now doubts that the greenish parts of the planet
are seas and oceans. But Venus and Mercury are never seen under
conditions enabling the observer to determine the colour of various
parts of their discs.
I may add that a mistake, somewhat analogous to that which I have
described in the cases of an imagined observer of our earth, has
been made by some spectroscopists in the case of the planets Jupiter
and Saturn. In considering the spectroscopic evidence respecting
the condition of these planets’ atmospheres, they have overlooked
the circumstance that we can judge only of the condition of the
outermost and coolest layers, for the lower layers are concealed
from view by the enormous cloud masses, floating, as the telescope
shows, in the atmospheric envelopes of the giant planets. Thus the
German spectroscopist Vögel argues that because in the spectrum
of Jupiter dark lines are seen which are known to belong to the
absorption-spectrum of aqueous vapour, the planet’s surface cannot be
intensely hot. But Jupiter’s absorption-spectrum belongs to layers of
his atmosphere lying far above his surface. We can no more infer the
actual temperature of Jupiter’s surface from the temperature of the
layers which produce his absorption-spectrum, than a visitor who should
view our earth from outer space, observing the low temperature of the
air ten or twelve miles above the sea-level, could infer thence the
actual temperature of the earth’s surface.
[3] In “Other Worlds than Ours,” I wrote as follows:—“The lines of
hydrogen, which are so well marked in the solar spectrum, are not seen
in the spectrum of Betelgeux. We are not to conclude from this that
hydrogen does not exist in the composition of the star. We know that
certain parts of the solar disc, when examined with the spectroscope,
do not at all times exhibit the hydrogen lines, or may even present
them as bright instead of dark lines. It may well be that in Betelgeux
hydrogen exists under such conditions that the amount of light it sends
forth is nearly equivalent to the amount it absorbs, in which case its
characteristic lines would not be easily discernible. In fact, it is
important to notice generally, that while there can be no mistaking
the positive evidence afforded by the spectroscope as to the existence
of any element in sun or star, the negative evidence supplied by the
absence of particular lines is not to be certainly relied upon.”
[4] Dr. Draper remarks here in passing, “I do not think that, in
comparisons of the spectra of the elements and sun, enough stress has
been laid on the general appearance of lines apart from their mere
position; in photographic representations this point is very prominent.”
[5] The word “ignited” may mislead, and indeed is not correctly used
here. The oxygen in the solar atmosphere, like the hydrogen, is simply
glowing with intensity of heat. No process of combustion is taking
place. Ignition, strictly speaking, means the initiation of the process
of combustion, and a substance can only be said to be ignited when it
has been set burning. The word _glowing_ is preferable; or if reference
is made to heat and light combined, then “glowing with intensity of
heat” seems the description most likely to be correctly understood.
[6] It would be an interesting experiment, which I would specially
recommend to those who, like Dr. Draper, possess instrumental means
specially adapted to the inquiry, to ascertain what variations, if any,
occur in the solar spectrum when (i.) the central part of the disc
alone, and (ii.) the outer part alone, is allowed to transmit light to
the spectroscope. The inquiry seems specially suited to the methods
of spectral photography pursued by Dr. Draper, and by Dr. Huggins, in
this country. Still, I believe interesting results can be obtained even
without these special appliances; and I hope before long to employ my
own telescope in this department of research.
[7] In 1860, a year of maximum sun-spot frequency, Cambridge won the
University boat-race; the year 1865, of minimum sun-spot frequency,
marked the middle of a long array of Oxford victories; 1872, the next
maximum, marked the middle of a Cambridge series of victories. May we
not anticipate that in 1878, the year of minimum spot frequency, Oxford
will win? [This prediction made in autumn, 1877, was fulfilled.] I
doubt not similar evidence might be obtained about cricket.
[8] It must be understood that this remark relates only to the theory
that by close scrutiny of the sun a power of predicting weather
peculiarities can be obtained, not to the theory that there may be
a cyclic association between sun-spots and the weather. If this
association exists, yet no scrutiny of the sun can tell us more than
we already know, and it will scarcely be pretended that new solar
observatories could give us any better general idea of the progress of
the great sun-spot period than we obtain from observatories already in
existence, or, indeed, might obtain from the observations of a single
amateur telescopist.
I think it quite possible that, from the systematic study of
terrestrial relations, the existence of a cyclic association between
the great spot period and terrestrial phenomena may be demonstrated,
instead of being merely surmised, as at present. By the way, it may be
worth noting that a prediction relative to the coming winter [that of
1877–78] has been made on the faith of such association by Professor
Piazzi Smyth. It runs as follows:—
“Having recently computed the remaining observations of our
earth-thermometers here, and prepared a new projection of all the
observations from their beginning in 1837 to their calamitous close
last year [1876]—results generally confirmatory of those arrived at in
1870 have been obtained, but with more pointed and immediate bearing on
the weather now before us.
“The chief features undoubtedly deducible for the past thirty-nine
years, after eliminating the more seasonal effects of ordinary summer
and winter, are:—
“1. Between 1837 and 1876 three great heat-waves, from without,
struck this part of the earth, viz., the first in 1846·5, the second
in 1858·0, and the third in 1868·7. And unless some very complete
alteration in the weather is to take place, the next such visitation
may be looked for in 1879·5, within limits of half a year each way.
“2. The next feature in magnitude and certainty is that the periods
of minimum temperature, or cold, are not either in, or anywhere near,
the middle time between the crests of those three chronologically
identified heat-waves, but are comparatively close up to them _on
either side_, at a distance of about a year and a half, so that the
next such cold-wave is due at the end of the present year [1877].
“This is, perhaps, not an agreeable prospect, especially if political
agitators are at this time moving amongst the colliers, striving to
persuade them to decrease the out-put of coal at every pit’s mouth.
Being, therefore, quite willing, for the general good, to suppose
myself mistaken, I beg to send you a first impression of plate 17 of
the forthcoming volume of observations of this Royal Observatory, and
shall be very happy if you can bring out from the measures recorded
there any more comfortable view for the public at large.
“PIAZZI SMYTH,
“Astronomer-Royal for Scotland.”
If this prediction shall be confirmed [this was written in autumn,
1877], it will afford an argument in favour of the existence of the
cyclic relation suggested, but no argument for the endowment of solar
research. Professor Smyth’s observations were not solar but terrestrial.
[The prediction was not confirmed, the winter of 1877–78 being, on the
contrary, exceptionally mild.]
[9] The reader unfamiliar with the principles of the telescope may
require to be told that in the ordinary telescope each part of the
object-glass forms a complete image of the object examined. If, when
using an opera-glass (one barrel), a portion of the large glass be
covered, a portion of what had before been visible is concealed. But
this is not the case with a telescope of the ordinary construction. All
that happens when a portion of the object-glass is covered is that the
object appears in some degree less fully illuminated.
[10] It may be briefly sketched, perhaps, in a note. The force
necessary to draw the earth inwards in such sort as to make her follow
her actual course is proportional to (i) the square of her velocity
directly, and (ii) her distance from the sun inversely. If we increase
our estimate of the earth’s distance from the sun, we, in the same
degree, increase our estimate of her orbital velocity. The square of
this velocity then increases as the square of the estimated distance;
and therefore, the estimated force sunwards is increased as the square
of the distance on account of (i), and diminished as the distance on
account of (ii), and is, therefore, on the whole, increased as the
distance. That is, we now regard the sun’s action as greater at this
greater distance, and in the same degree that the distance is greater;
whereas, if it had been what we before supposed it, it would be less
at the greater distance as the square of the distance (attraction
varying inversely as the square of the distance). Being greater as the
distance, instead of less as the square of the distance, it follows
that our estimate of the sun’s absolute force is now greater as the
cube of the distance. Similarly, if we had diminished our estimate
of the sun’s distance, we should have diminished our estimate of his
absolute power (or mass) as the cube of the distance. But our estimate
of the sun’s volume is also proportional to the cube of his estimated
distance. Hence our estimate of his mass varies as our estimate of his
volume; or, our estimate of his mean density is constant.
[11] Only very recently an asteroid, Hilda (153rd in order of
detection), has been discovered which travels very much nearer to the
path of Jupiter than to that of Mars—a solitary instance in that
respect. Its distance (the earth’s distance being represented by
unity), is 3·95, Jupiter’s being 5·20, and Mars’s 1·52; its period
falls short of 8 years by only two months, the average period of the
asteroidal family being only about 4½ years. Five others, Cybele,
Freia, Sylvia, Camilla, and Hermione, travel rather nearer to Jupiter
than to Mars; but the remaining 166 travel nearer to Mars, and most of
them much nearer.
[12] Even this statement is not mathematically exact. If the rails are
straight and parallel, the ratio of approach and recession of an engine
on one line, towards or from an engine on the other, is never quite
equal to the engines’ velocities added together; but the difference
amounts practically to nothing, except when the engines are near each
other.
[13] I have omitted all reference to details; but in reality the
double battery was automatic, the motion of the observing telescope,
as different colours of the spectrum were brought into view, setting
all the prisms of the double battery into that precise position which
causes them to show best each particular part of the spectrum thus
brought into view. It is rather singular that the first view I ever had
of the solar prominences, was obtained (at Dr. Huggins’s observatory)
with this instrument of my own invention, which also was the first
powerful spectroscope I had ever used or even seen.
[14] It varies more in some months than in others, as the moon’s orbit
changes in shape under the various perturbing influences to which she
is subject.
[15] It may seem strange to say that one hundred and twenty years after
the passage of a comet which last passed in 1862, and was then first
discovered, August meteors have been seen. But in reality, as we know
the period of that comet to be about one hundred and thirty years, we
know that the displays of the years 1840, 1841, etc., to 1850, must
have followed the preceding passage by about that interval of time.
[16] The D line, properly speaking, as originally named by Fraunhofer,
belongs to sodium. The line spoken of above as the sierra D line is
one close by the sodium line, and mistaken for it when first seen in
the spectrum of the coloured prominences as a bright line. It does not
appear as a dark line in the solar spectrum.
[17] Since this was written, I have learned that Mr. Backhouse, of
Sunderland, announced similar results to those obtained at Dunecht, as
seen a fortnight or so earlier.
[18] Here no account is taken of the motions of the stars within the
system; such motions must ordinarily be minute compared with the common
motion of the system.
[19] Eight pictures of nebulæ were exhibited in illustration of this
peculiarity.
[20] Sir John Herschel long since pointed to the variation of our sun
as a possible cause of such changes of terrestrial climate.
[21] During these journeys the Atlantic was sounded, and Scoresby’s
estimate of the enormous depth of the Atlantic to the north-west of
Spitzbergen was fully confirmed, the line indicating a depth of more
than two miles. It was found also that Spitzbergen is connected with
Norway by a submarine bank.
[22] It is far from improbable that a change has taken place in the
climate of the part of the Arctic regions traversed by Koldewey; for
the Dutch seem readily to have found their way much further north two
centuries ago. Indeed, among Captain Koldewey’s results is one which
seems to indicate the occurrence of such a change. The country he
explored was found to have been inhabited. “Numerous huts of Esquimaux
were seen, and various instruments and utensils of primitive form;
but for some reason or other the region seems to have been finally
deserted. The Polar bear reigns supreme on the glaciers, as the walrus
does among the icebergs.” Not improbably the former inhabitants were
forced to leave this region by the gradually increasing cold.
[23] Dr. Emile Bessels was tried at New York in 1872, on the charge of
having poisoned Captain Hall, but was acquitted.
[24] The phenomena here described are well worth observing on their
own account, as affording a very instructive and at the same time very
beautiful illustration of wave motions. They can be well seen at many
of our watering-places. The same laws of wave motion can be readily
illustrated also by throwing two stones into a large smooth pool, at
points a few yards apart. The crossing of the two sets of circular
waves produces a wave-net, the meshes of which vary in shape according
to their position.
[25] It is a pity that men of science so often forget, when addressing
those who are not men of science, or who study other departments than
theirs, that technical terms are out of place. Most people, I take it
are more familiar, on the whole, with eyelids than with _palpebræ_.
[26] This nautical expression is new to me. Top-gallants—fore,
main, and mizen—I know, and forecastle I know, but the top-gallant
forecastle I do not know.
[27] The instrument was lent to Mr. Huggins by Mr. W. Spottiswoode. It
has been recently employed successfully at Greenwich.
[28] Thus in _Christie Johnstone_, written in 1853, when Flucker
Johnstone tells Christie the story of the widow’s sorrows, giving
it word for word, and even throwing in what dramatists call “the
business,” he says, “‘Here ye’ll play your hand like a geraffe.’
‘Geraffe?’ she says; ‘that’s a beast, I’m thinking.’ ‘Na; it’s the
thing on the hill that makes signals.’ ‘Telegraph, ye fulish goloshen!’
‘Oo, ay, telegraph! geraffe’s sunnest said for a’.’” “Playing the hand
like a telegraph” would now be as unmeaning as Flucker Johnstone’s
original description.
[29] Not “to represent the gutta-percha,” as stated in the _Times_
account of Mr. Muirhead’s invention. The gutta-percha corresponds
to the insulating material of the artificial circuit; viz., the
prepared paper through which the current along the tinfoil strips acts
inductively on the coating of tinfoil.
[30] I must caution the reader against Fig. 348 in Guillemin’s
_Application of the Physical Forces_, in which the part _c d_ of the
wire is not shown. The two coils are in reality part of a single coil,
divided into two to permit of the bar being bent; and to remove the
part _c d_ is to divide the wire, and, of course, break the current. It
will be seen that _c d_ passes from the remote side of coil _b c_, Fig.
6, to the near side of coil _d e_. If it were taken round the remote
side of the latter coil, the current along this would neutralize the
effect of the current along the other.
[31] The paper is soaked in dilute ferrocyanide of potassium, and the
passage of the current forms a Prussian blue.
[32] Sir W. Thomson states, in his altogether excellent article on the
electric telegraph, in Nichol’s _Cyclopædia_, that the invention of
this process is due to Mr. Bakewell.
[33] It is to be noticed, however, that the recording pointer must
always mark its lines in the same direction, so that, unless a message
is being transmitted at the same time that one is being received (in
which case the oscillations both ways are utilized), the instrument
works only during one-half of each complete double oscillation.
[34] It seems to me a pity that in the English edition of this work
the usual measures have not been substituted throughout. The book is
not intended or indeed suitable for scientific readers, who alone are
accustomed to the metric system. Other readers do not care to have a
little sum in reduction to go through at each numerical statement.
[35] Hanno’s _Periplus_—the voyage of Hanno, chief of the
Carthaginians, round the parts of Libya, beyond the Pillars of
Hercules, the narrative of which he posted up in the Temple of Kronos.