-----
The opinion of the earth’s rotation on its axis was once violently
opposed, from a notion of its dangerous tendency with respect to the
interests of religion:[A34] But, as truth is always consistent with
itself, so many new proofs were furnished from time to time by new
discoveries, that a mistaken interpretation of some passages in the
bible was compelled to give way to the force of astronomical evidence.
The doctrine of a plurality of worlds, is inseparable from the
principles of Astronomy; but this doctrine is still thought, by some
pious persons, and by many more I fear, who do not deserve that title,
to militate against the truths asserted by the Christian religion. If I
may be allowed to give my opinion on a matter of such importance, I must
confess that I think upon a proper examination the apparent
inconsistency will vanish. Our religion teaches us what philosophy could
not have taught; and we ought to admire with reverence the great things
it has pleased divine Providence to perform, _beyond the ordinary course
of Nature_, for man, who is undoubtedly the most noble inhabitant of
this globe. But neither religion nor philosophy forbids us to believe
that infinite wisdom and power, prompted by infinite goodness, may
throughout the vast extent of creation and duration, have frequently
interposed in a manner quite incomprehensible to us, when it became
necessary to the happiness of created beings of some other rank or
degree.
-----
Footnote A34:
In 745, Virgilus, bishop of Saltzburg, having publicly asserted in
some of his sermons, that there were antipodes, he was charged with
heresy, by Boniface, bishop of Mentz, and cited to appear before the
Pope, who recommended the hearing of the cause to Utilo, King of
Bohemia, and at the same time wrote to him in favour of Boniface. The
event was, the bishop of Saltzburg lost his cause, and was condemned
for heresy.
-----
How far indeed the inhabitants of the other planets may resemble man, we
cannot pretend to say. If like him they were created liable to fall, yet
some, if not all of them, may still retain their original rectitude. We
will hope they do: the thought is comfortable.—Cease, Galileo, to
improve thy optic tube: and thou, great Newton, forbear thy ardent
search into the distant mysteries of nature: lest ye make unwelcome
discoveries. Deprive us not of the pleasure of believing that yonder
radiant orbs, traversing in silent majesty the etherial regions, are the
peaceful seats of innocence and bliss: where neither natural nor moral
evil has ever yet intruded; where to enjoy with gratitude and adoration
the creator’s bounty, is the business of existence. If their inhabitants
resemble man in their faculties and affections, let us suppose that they
are wise enough to govern themselves according to the dictates of that
reason their creator has given them, in such manner as to consult their
own and each other’s true happiness, on all occasions. But if, on the
contrary, they have found it necessary to erect artificial fabrics of
government, let us not suppose that they have done it with so little
skill, and at such an enormous expence, as must render them a misfortune
instead of a blessing. We will hope that their statesmen are patriots,
and that their kings, if that order of beings has found admittance
there, have the feelings of humanity.—Happy people! and perhaps more
happy still, that all communication with us is denied. We have neither
corrupted you with our vices, nor injured you by violence. None of your
sons and daughters, degraded from their native dignity, have been doomed
to endless slavery by us in America, merely because _their_ bodies may
be disposed to reflect or absorb the rays of light, in a way different
from _ours_. Even you, inhabitants of the moon, situated in our very
neighbourhood, are effectually secured, alike from the rapacious hand of
the haughty Spaniard, and of the unfeeling British nabob. Even British
thunder impelled by British thirst of gain, cannot reach you: And the
utmost efforts of the mighty Frederick, that tyrant of the north and
scourge of mankind, if aimed to disturb _your_ peace, becomes
inconceivably ridiculous and impotent.
Pardon these reflections; they rise not from the gloomy spirit of
misanthropy. That being, before whose piercing eye all the intricate
foldings and dark recesses of the human heart become expanded and
illuminated, is my witness with what sincerity, with what ardor, I wish
for the happiness of the whole race of mankind: how much I admire that
disposition of lands and seas, which affords a communication between
distant regions, and a mutual exchange of benefits:[A35] how sincerely I
approve of those social refinements which really add to our happiness,
and induce us with gratitude to acknowledge our great Creator’s
goodness:—how I delight in a participation of the discoveries made from
time to time in nature’s works, by our Philosophic brethren in Europe.
-----
Footnote A35:
It has been shewn, in a preceding note, how much the means of
communicating between distant regions, separated by seas, ware
facilitated by the discovery and use of the Compass: but those means
have been still further and very greatly improved, since the
introduction of the use of the Quadrant at sea, especially that called
Hadley’s Quadrant.
The true inventor of the reflecting Quadrant was Dr. Robert Hook, a
very ingenious English mathematician and philosopher, who died in the
year 1702, at the age of sixty-seven years. This instrument, now
commonly styled Hadley’s, was afterwards rendered much more complete
than Dr. Hook’s invention had made it, by Sir Isaac Newton: but our
modern artists, more skilful than those of former times, as Mr.
Lalande has observed, have profited of the ideas of the great Newton
himself, on the subject; and among the later improvers of the Sea
Quadrant, or Octant, is Mr. Hadley, whose name the instrument usually
bears.
It would, however, be doing an act of injustice to the memory of an
American who possessed an extraordinary genius, to omit, in the course
of these memoirs, some notice of his merits in relation to this
matter. Mr. Thomas Godfrey, a native of Pennsylvania, is said to have
turned his attention to this subject, so early as the year 1730; and
in the Transactions of the Royal Society of London, No. 435, will be
found, an “_Account of Mr. Thomas Godfrey’s Improvement of Davis’s
Quadrant transferred to the Mariner’s Bow_,” drawn up by James Logan,
Esq. formerly of Philadelphia, a gentleman of extensive learning, and
a very eminent mathematician, Mr. Godfrey is stated to have “sent the
instrument (which he had constructed) to be tried at sea by an
acquaintance of his, an ingenious navigator, in a voyage to Jamaica,
who shewed it to a captain of a ship there, just going for England; by
which means, it came to the knowledge of Mr. Hadley, though perhaps
without his being told the name of the real inventor.” [See _The
American Magazine_, for July 1758.] In a letter, dated at Philadelphia
the 25th of May, 1732, Mr. Logan, who very ably as well as
meritoriously patronized Godfrey, communicated to the celebrated Dr.
Edmund Halley a detailed account and description of the _improved_
Sea-Quadrant constructed by that ingenious citizen of America, of
which his patron confidently believed him to be the original inventor.
On the 28th of June, 1734, a further account of Godfrey’s invention
was drawn up by Mr. Logan, and subscribed with his name; which, it is
presumed, was also communicated to the Royal Society: and on the 9th
of November, in the same year, Mr. Godfrey transmitted an account of
it, draughted and signed by himself, to the same learned body. The
whole of these interesting letters, with some accompanying
observations on the subject, are published in the valuable _Magazine_
just referred to, and in the one for the succeeding month.
In the Transactions of the Royal Society, for the months of October,
November and December, 1731, No. 421, is contained a Proposal, by Dr.
Edmund Halley, for finding the longitude at sea, within a degree or
twenty leagues, &c. In the conclusion of this paper, Dr, Halley, in
speaking of John Hadley, Esq. VP.R.S, (“to whom,” as he observes, “we
are highly obliged for his having perfected and brought into common
use the reflecting telescope,”) says—He “has been pleased to
communicate _his_ most ingenious instrument for taking the angles _by
reflection_,” (referring, here, to the Philos. Trans. No. 420;) “it is
more than probable that the same may be applied to taking angles _at
sea_, with the desired accuracy.”
In Mr. Logan’s account of Mr. Godfrey’s invention, dated June 28,
1734, he says: “Tis now four years since Thomas Godfrey hit on this
improvement; for, his account of it, laid before the (Royal) Society
last winter, in which he mentioned two years, was wrote in 1732; and
in the same year, 1730, after he was satisfied in this, he applied
himself to think of the other, viz. _the reflecting instrument, by
speculums for a help in the case of longitude_, though ’tis also
useful in taking altitudes: and one of these, as has been abundantly
proved by the maker, and those who had it with them, was taken to sea
and there used in observing the latitudes the winter of that year, and
brought back again to Philadelphia before the end of February 1730–1,
and was in my keeping some months immediately after.”
In Mr, Logan’s prior letter to Dr. Halley (dated May 25, 1732,) he
says, that about eighteen months before, Godfrey told him, “he had for
some time before been thinking of an instrument for taking the
distances of stars by reflecting speculums, which he believed might be
of service “at sea;” and that, soon after, Godfrey shewed him an
instrument, which he had procured to be made, for the purpose. Thus,
the time to which Mr. Logan refers Godfrey’s communication of his
improvement to him, would make its date to be about the month of
November, 1730.
In the Rev. Mr. Vince’s great work, entitled, _A Complete System of
Astronomy_, (and contained in “A Treatise on Practical Astronomy,” at
the end of the second volume of that work,) is an entire chapter on
“_Hadley’s Quadrant_;” giving a particular description of the
instrument, with rules for the computations from the observations and
illustrations of them by examples. In this Treatise, the author says,
that the instrument took its name from the “inventor,” John Hadley,
Esq. and observes, that not only the science of navigation is greatly
indebted, to this “incomparable instrument,” but such are its various
uses in astronomy, that it may not improperly be called “a portable
observatory.” Mr. Vince further observes, that in the year 1742, about
ten years after Mr. Hadley’s invention (for so he styles it) was
published, a paper in Sir Issac Newton’s own hand-writing was found
among Dr. Halley’s papers, after the Doctor’s death, containing a
figure and description of an instrument (referring to _Philos.
Transactions_, No. 465,) not much different in its principle from this
of Hadley. He adds, that as Dr. Halley was alive when Mr. Hadley’s
instrument was shewn to the Royal Society, and he took no notice of
this paper of Sir Isaac Newton, it is probable he did not know there
was such an one. In another part of his work (under the head of _The
History of Astronomy_, vol. ii. p. 280.) Mr. Vince asserts, that the
first person who formed the idea of making a Quadrant to take angles
by reflection, was Robert Hook; and he was born in 1635. On the whole,
however, the learned author draws this conclusion:—“Both Sir Isaac
Newton and Mr. Hadley therefore seem entitled to this invention.”
Mr. Lalande, speaking of this instrument, says: “Le Quartier de
Reflexion, exécuté en 1731 par Hadley, a donné un moyen facile de
mesurer les distances sur mer, à une minute pris, aussi bien
determiner le lieu de la Lune en mer.” See his _Astronomie_, vol. iii.
p. 654.
From these facts, and a careful examination of the papers themselves,
here quoted and referred to, the scientific reader will be enabled to
decide upon the true merits of the controversy that has so long
subsisted, concerning the respective claims of Godfrey and of Hadley,
to the invention of the instrument that bears the name of the latter.
Before this subject is dismissed, however, it will not be deemed
improper to add, that the late Dr. John Ewing communicated to the Am.
Philosophical Society an account of an Improvement in the construction
of (what he terms) “Godfrey’s double reflecting Quadrant,” which he
had discovered in the spring or summer of the year 1767: this will be
found in the first volume of the Society’s Transactions. In the
conclusion of this communication, Dr. Ewing says:—“This improvement of
an instrument, which was first invented and constructed by Mr. Godfrey
of this city, and which I do not hesitate to call the most useful of
all astronomical instruments that the world ever knew, I hope will
make it still more serviceable to mankind.”
This communication to the Society by Dr. Ewing, was made in the year
1770. In one concerning the comet of that year, and made by Dr.
Rittenhouse about the same time, the instrument to which Dr. Ewing’s
improvement applies, is called Hadley’s Quadrant: but perhaps Dr.
Rittenhouse so named it, in conformity to common usage.
-----
But when I consider, that _luxury_ and her constant follower _tyranny_,
who have long since laid in the dust, never to rise again, the glories
of Asia, are now advancing like a torrent irresistible, whose weight no
human force can stem, and have nearly completed their conquest of
Europe; luxury and tyranny, who by a vile affectation of virtues they
know not, pretend at first to be the patrons of science and philosophy,
but at length fail not effectually to destroy them; agitated I say by
these reflections, I am ready to wish—vain wish! that nature would raise
her everlasting bars between the new and old world; and make a voyage to
Europe as impracticable as one to the moon. I confess indeed, that by
our connections with Europe we have made most surprising, I had almost
said unnatural, advances towards the meridian of glory; but by those
connections too, in all probability, our fall will be premature. May the
God of knowledge inspire us with wisdom to prevent it: let our harbours,
our doors, our hearts, be shut against luxury. But I return to my
subject, and will no longer indulge these melancholy thoughts.
Some have observed, that the wonderful discoveries of the microscope
ought to go hand in hand with those of the telescope; lest whilst we
contemplate the many instances of the wisdom and power of divine
Providence, displayed in the great works of creation, we should be
tempted to conclude that man, and other less important beings of this
lower world, did not claim its attention. But I will venture to affirm,
without at all derogating from the merits of those who have so greatly
obliged the world with the success of their microscopical enquiries,
that no such danger is to be apprehended. Nothing can better demonstrate
the immediate presence of the Deity in every part of space, whether
vacant or occupied by matter, than astronomy does. It was from an
astronomer St. Paul quoted that exalted expression, so often since
repeated; “_In God we live, and move, and have our being_.” His divine
energy supports that universal _substratum_ on which all corporal
substances subsist, that the laws of motion are derived from, and that
wings _light_ with angelic swiftness.
If the time would permit, how agreeable the task to dwell on the praises
of Astronomy: to consider its happy effects as a science, on the human
mind. Let the sceptical writers forbear to lavish encomiums on their
cobweb Philosophy, liable to be broken by the smallest incident in
nature. They tell us it is of great service to mankind, in banishing
bigotry and superstition from amongst us. Is not this effectually done
by Astronomy? The direct tendency of this science is to dilate the heart
with universal benevolence, and to enlarge its views. But then it does
this without propagating a single point of doctrine contrary to common
sense, or the most cultivated reason. It flatters no fashionable
princely vice, or national depravity. It encourages not the libertine by
relaxing any of the precepts of morality; nor does it attempt to
undermine the foundations of religion. It denies none of those
attributes, which the wisest and best of mankind, have in all ages
ascribed to the Deity: Nor does it degrade the human mind from that
dignity, which is ever necessary to make it contemplate itself with
complacency. None of these things does Astronomy pretend to; and if
these things merit the aim of Philosophy, and the encouragement of a
people, then let scepticism flourish, and Astronomy lie neglected; then
let the names of Berkeley, and Hume, become immortal, and that of Newton
be lost in oblivion.
I shall conclude this part of my discourse with the words of Dr.
Barrow—It is to Astronomy we owe “that we comprehend the huge fabric of
the universe, admire and contemplate the wonderful beauty of the divine
workmanship, and so learn the invincible force and sagacity of our own
minds, as to acknowledge the blessings of heaven with a pious
affection.”
I now come, in the last place, to point out some of the defects of
Astronomy at this day. Which I am induced to undertake by the hopes I
entertain that some of those defects may be removed under the auspices
of this society, and of you my fellow citizens, who have so zealously
promoted its institution. “The advantages arising from Astronomy, the
pleasure attending the study of it, the care with which it was
cultivated by many great men among the ancients, and the extraordinary
attention paid to it in Europe by the present age,” all contribute to
recommend it to your protection, under which we have the best reason to
expect that it will flourish.
The mildness of our climate and the serenity of our atmosphere, perhaps
not inferior to that of Italy, and likewise our distant situation from
the principal observatories in the world (whence many curious phænomena
must be visible here that are not likely to be observed any where else)
are so many circumstances greatly in our favour.
And I trust there will not be wanting men of genius, to arise in this
new world, whose talents may be particularly adapted to astronomical
enquiries. Indeed I am persuaded that nature is by no means so nigardly
in producing them, as we are apt to imagine. Some are never tempted
forth from obscurity, some are untimely snatched away by death, a
striking instance whereof we have in Horrox; and many are accidentally
led to other pursuits.
The Astronomy of comets is still in its infancy; not that the attention
of the learned and ingenious has at all been wanting for more than a
century past; but because it will necessarily require many ages to bring
it to perfection. I wish we were in a condition to promote it in some
degree, by carefully observing such comets as may appear. As yet we
scarce dare affirm that any one has or will return a second time. It has
never, that I know of, been certainly proved by observation, that a
comet has descended within a parabolic orbit, and until that is done we
have only a coincidence of periods and orbits (none of which have been
very precise) to depend on for their return. Far less are astronomers
able to determine the changes that may, and probably do, happen in their
orbits[A36] and velocities in every period, so as to predict their
nearer or more remote approach to the earth or any planet. Whether their
business be to repair or destroy, whether they are worlds yet in
formation or once habitable worlds in ruins; whether they are at present
habitable and regular attendants of our Sun only, or whether they are
the vast links that connect the distant parts of creation by surrounding
more suns than one, we know not.
-----
Footnote A36:
This I know has been pretended to. But it is easy to make geometrical
conclusions come out as we would have them, when the data they are
founded on, are so uncertain that we may chuse them as suits our
purpose.
-----
If we descend to the Planetary System, there are still many things
wanting to compleat Astronomy.
The orbits of the primary planets have at one time been supposed
moveable with various irregularities, at other times fixed and
permanent. It seems now generally granted, that according to the theory
of gravity they must change their situations; yet not long since, some
great astronomers warmly contended that this change was altogether
insensible.
According to the best tables we now have, the planes of the orbits of
Jupiter, the Earth and Mercury are immoveable, though the orbits
themselves have a progressive motion in their planes. On the contrary,
the poles of the orbits of Saturn, Mars and Venus are supposed to
revolve about the poles of the earth’s orbit, with such velocities as at
present nearly reconcile calculation to appearances. But there is good
reason to apprehend that such a supposition is not true in fact, and a
mistake in this matter will have some important consequences. More
probable is it, that the poles of the orbits of all the planets, the
earth not excepted, revolve about some common centre. The several
quantities of these motions, I am confident, are to be had from
observation, and not from theory alone. If such a motion of the earth’s
orbit be admitted, it will account for the diminution[A37] of the
obliquity of the ecliptic; which seems now incontestible; and that in
whatever manner we divide the forces producing such motion, amongst the
two superior planets and Venus, or even amongst all of them. And I
should suspect the further diminution of obliquity, from this cause,
will amount to about one degree and an half.
-----
Footnote A37:
This circumstance tends gradually to lessen the variety of the
seasons.
-----
But as Astronomy now stands, it seems doubtful whether this change is
owing to a deviation in the diurnal or annual motion of the earth; which
introduces a very disagreeable uncertainty in conclusions drawn from
some nice and useful observations.
The Lunar Astronomy has been brought so much nearer to perfection, by
the celebrated MAYER,[A38] than could have been expected, that I shall
mention no deficiency in it, but this. We do not certainly know whether
that apparent acceleration of the moon’s motion, which Mayer with other
great astronomers has admitted, ought to be attributed to a real
increase of velocity in the moon, or to a diminution of the earth’s
diurnal motion. If to the former, the destruction of this beautiful and
stupendous fabric, may from thence be predicted with more certainty than
from any other appearance in Nature: But if to the latter, it may be
prettily accounted for, by Dr. Halley’s ingenious hypotheses concerning
the change of variation in the magnetical needle. The Doctor supposes
the external crust or shell of the earth to contain a nucleus detatched
from it, and that the impulse which first caused the diurnal motion, was
given to the external parts, and from thence in time communicated to the
internal nucleus, by means of an intervening fluid; but not so as
perfectly to equal the velocity of the superficial parts of the globe.
Whence it will follow, that the external shell of the earth is still
communicating motion to the internal parts, and losing motion itself
proportionably. The diurnal motion must therefore become slower and
slower, yet can never be retarded, by this cause, beyond certain limits;
nor can we conceive that any inconvenience will follow.
-----
Footnote A38:
This was Tobias Mayer, who was born at Marbach in the principality of
Wurtemberg, in the year 1723: he rendered himself celebrated in
astronomy, by having calculated the best tables of the moon, and by an
excellent catalogue of stars. He died at Gottingen in 1762, at the age
of thirty-nine years. W. B.
-----
There is another physical question relating to the moon, which to me
appears extremely curious; it is this—Whence is it that the moon always
turns the same side to us? or, which is the same thing, How comes the
moon’s rotation on her axis, and her monthly revolution about the earth,
to be performed in the same time? None I believe will suppose it to be
accidental, nor will the astronomer be easily satisfied with a final
cause. Was it not originally brought about by a natural cause which
still subsists? Can the attraction of any foreign body change a rotatory
motion into a libratory one, and a libratory motion into rest, in spaces
so very free from all resistance as those wherein the planets move?
There are other defects in Astronomy that are purely optical. Removing
of those, depends on the further improvement of telescopes, or rather on
the more judicious use of them, at times and places the most favourable.
In speaking of telescopic discoveries I purposely reserved those made on
Venus for this place, because they are still uncertain. Burratini in
Poland first discovered spots in Venus, then Cassini in Italy; and
afterwards Bianchini got a sight of them. But from all their
observations it is uncertain, whether Venus revolves on its axis once in
23 hours, or once in 24 days. Perhaps it does neither. Nor is their
determination of the axis’ situation much more satisfactory. These spots
on Venus are not to be seen but through an excellent telescope and a
pure atmosphere.
In the year 1672 and 1676 Cassini saw a small star near Venus, which he
thought might be a satellite attending on her. It appeared to have the
same phase with Venus. In 1740 Mr. Short with a telescope of 16 inches
saw a small star at the distance of ten minutes from Venus, which from
its apparent shape he likewise thought might be a satellite. And in 1761
Mr. Montaigne, in France, saw what he took to be the satellite of Venus,
on the 3d, 4th, 7th and 11th of May.[A39] But whether Venus has a
satellite or not, must still be left amongst the doubtful things of
Astronomy.
-----
Footnote A39:
It may happen that any of the planets, about the time they become
stationary, shall describe a loop about some small fixed star, in such
manner as might be easily mistaken for the star making part of a
revolution about the planet. This I suspected to have been the case
with the above observation of Montaigne. But the times set down do not
confirm the suspicion.
-----
The spots on the sun, and those on the surfaces of several planets, have
been many years observed without our approaching any nearer towards
discovering their nature and cause. Dr. Wilson of Glasgow, has lately
succeeded in advancing one step at least, with respect to those of the
sun. He has proved from observation that those spots are vast cavities,
whose bottoms lie far below the general surface of the sun, and whose
sloping sides form the border which we generally see surrounding them.
If I should venture to add one conjecture of my own, to those of this
ingenious gentleman, I would suppose that those prodigious cavities in
the surface of the sun, some of them capable of containing half our
earth, are not repeatedly formed by unaccountable explosions of a
semifluid substance, but permanent and solid, like the cavities within
the moon. And that it is the dark matter sometimes lodging in them, that
distinguishes them, and is only accidental.
The diurnal rotations of Saturn and Mercury are yet unknown; but when
further improvements shall be made in the art of using telescopes, this
circumstance will hardly escape the vigilance of astronomers.
These are a few of the many things that are still left to the industry
of the ingenious in this science.
But if all higher and more sublime discoveries are not reserved for us
in a future and more perfect state; if Astronomy shall again break those
limits that now seem to confine it, and expatiate freely in the superior
celestial fields; what amazing discoveries may yet be made amongst the
fixed stars! That grand phænomenon the Milky-Way seems to be the clue
that will one day guide us. Millions of small stars compose it, and many
more bright ones lie in and near it, than in other parts of heaven. Is
not this a strong indication that this astonishing system of worlds
beyond worlds innumerable, is not alike extended every way, but confined
between two parallel planes, of _immeasureable_, though not _infinite_
extent? Or rather, is not the Milky-Way a vein of a closer texture,
running through this part of the material creation? Great things are
sometimes best explained by small and small by great. Material
substances, such as we daily handle, have been thought composed of
impenetrable particles in actual contact: then again it has seemed
necessary to suppose them at a distance from each other, and kept in
their relative situations by _attraction_ and _repulsion_. Many
appearances require that those distances should be very great in
proportion to the size of the particles. Hence some, with no small
reason, have concluded that matter consists of indivisible points endued
with certain powers. Let us compare these smaller portions of it with
that great aggregate of matter which is the object of Astronomy; _Light_
will then appear to have as free passage through a piece of glass, as
the comets have in the planetary regions; and several other new
considerations will arise.
If instead of _descending_ we _ascend_ the scale. If we consider that
infinite variety which obtains in those parts of nature with which we
are most intimate: how one order of most curiously organized bodies,
infinitely diversified in other respects, all agree in being fixed to
the earth, and receiving nourishment from thence: how another order have
spontaneous motion, and seek their food on different parts of the earth,
whilst by gravity they are confined to its surface, but in other
respects diversified like the former. How a _third_ float in, and below
the surface of, a dense fluid, of equal weight with their bodies, which
would soon prove fatal to both the others: And a _fourth_ consisting of
a vast variety too, have this property in common, that by a peculiar
mechanism of their bodies, they can soar to great heights above the
earth, and quickly transport themselves to distant regions in a fluid so
rare as to be scarcely sensible to us. But not to pursue this boundless
subject any further, I say, when we consider this great variety so
obvious on _our_ globe, and ever connected by some degree of uniformity,
we shall find sufficient reason to conclude, that the visible creation,
consisting of revolving worlds and central suns, even including all
those that are beyond the reach of human eye and telescope, is but an
inconsiderable part of the whole. Many other and very various orders of
things unknown to, and inconceivable by us, may, and probably do exist,
in the unlimited regions of space. And all yonder stars innumerable,
with their dependencies, may perhaps compose but the leaf of a flower in
the Creator’s garden, or a single pillar in the immense building of the
Divine Architect.
Here is ample provision made for the all-grasping mind of man!
If it shall please that Almighty Power who hath placed us in a world,
wherein we are only permitted “_to look about us and to die_;” should it
please him to indulge us with existence throughout that half of eternity
which still remains unspent; and to conduct us through the several
stages of his works; here is ample provision made for employing every
faculty of the human mind, even allowing its powers to be constantly
enlarged through an endless repetition of ages. Let us not complain of
the vanity of this world, that there is nothing in it capable of
satisfying us: happy in those wants, happy in those restless desires,
forever in succession to be gratified; happy in a continual approach to
the Deity.
I must confess that I am not one of those sanguine spirits who seem to
think, that when the withered hand of death hath drawn up the curtain of
eternity, almost all distance between the creature and creator, between
finite and infinite, will be annihilated. Every enlargement of our
faculties, every new happiness conferred upon us, every step we advance
towards the perfection of the divinity, will very probably render us
more and more sensible of his inexhaustible stores of communicable
bliss, and of his inaccessible perfections.
Were we even assured that we shall perish like the flowers of the
garden, how careful would a wise man be to preserve a good conscience,
during the short period of his existence; because by his very
constitution, which he cannot alter, this is his pride and glory, and
absolutely necessary to his present happiness; because this would insure
to him at the approach of death, the soothing reflection, that he was
going to restore, pure and uncorrupted, that drop of divinity within
him, to the original ocean from whence it was separated. How much more
anxiously careful ought we to be, if we believe, as powerful arguments
compel us to believe, that a conduct in this life depending on our own
choice, will stamp our characters for ages yet to come. Who can endure
the thought of darkening his faculties by an unworthy application of
them here on earth, and degrading himself to some inferior rank of
being, wherein he may find both his power and inclination to obtain
wisdom and exercise virtue, exceedingly diminished? On the other hand,
if that humble admiration and gratitude, which sometimes rises in our
minds when we contemplate the power, wisdom and goodness of the Deity,
constitutes by far the most sublimely happy moments of our lives, and
probably will forever continue to do so, there cannot be a stronger
incitement to the exercise of virtue and a rational employment of those
talents we are entrusted with, than to consider that by these means we
shall in a few years be promoted to a more exalted rank amongst the
creatures of God, have our understandings greatly enlarged, be enabled
to follow truth in all her labyrinths with a higher relish and more
facility, and thus lay the foundation of an eternal improvement in
knowledge and happiness.
---
[TRANSLATED FROM THE LATIN ORIGINAL.]
_To the illustrious and celebrated Society of Sciences, at
Philadelphia_,
CHRISTIAN MAYER, Astronomer to the most serene Prince, the Elector
Palatine, wisheth prosperity.
I have concluded on due reflection, that the opportunity of writing,
afforded me by the eminent Mr. Ferdinando Farmer, ought the less to be
neglected, as by this means I might make some small return for the
honour which the illustrious Society conferred on me, when they
enrolled me in the list of their members.
I learnt with great pleasure, by a work printed in Philadelphia, and
transmitted to me about three years since, that even there Astronomy
is cultivated. That book, together with my own astronomical papers,
having been destroyed by an unfortunate fire about two years ago, I
have been induced to address something to your illustrious Society,
concerning some of my new discoveries in the heavens.
I occupy a new Observatory at Manheim, accommodated to all
astronomical purposes: nor is it deficient in any of the most valuable
London-made instruments. Among these, the one which principally
excels, is a mural quadrant of brass, of eight feet radius, made by
that celebrated artist Bird, in the year 1776; fitted with an
achromatic telescope, and firmly affixed to a wall, in the meridian;
which I use daily, when the weather permits. I observed, nearly two
years since, that, among the fixed stars, many of them from the first
to the sixth degree of magnitude, other small attendant stars (or
satellites) were distinguishable: some of which, by reason of their
steady and dim light, resemble an order of planets, while others do
not exceed the smallness of the telescopic size. The circumstance
which principally excited my surprize, is, that I found none of those
little attendant stars, a very few only excepted, contained in any
known catalogue; although I could clearly discover that their use, for
the purpose of determining the proper motion of the fixed stars, is
very obvious. For where the difference of right ascension and
declination, of a few seconds at most, is found between the brighter
fixed star and its attendant, the lapse of time could scarcely give
any other variation to the fixed star, than to its satellite: from
what cause soever that variation may arise, whether from the
precession of the equinoxes, the variation in the obliquity of the
ecliptic, the deviation of the instrument, or from the aberration of
light or the nutation, or from any other cause whatever, which may
depend on the mutable state of the atmosphere or the latitude of
places, the fact is evident, that every change of situation, observed,
between the fixed star and its satellite, affords the most certain
proof of its actual motion; whether this be referred to the fixed star
or its satellite.
I knew that Halley, the celebrated English astronomer, was the first,
who, in the year 1719, from an actual comparison of Flamstead’s
observations with those of Ptolemy, respecting some few fixed stars,
Syrius, Arcturus, and Aldebaran, discovered that these stars moved,
with a motion peculiar to themselves: But I knew at the same time,
that in Flamstead’s British Celestial History, so long ago as the year
1690, the name of attendant (or satellite) was assumed by Flamstead;
when that great man had not even thought of the proper motion of the
fixed stars.
Other astronomers, since the time of Halley, so far as they examined
the proper motion of the fixed stars, have followed the Halleian
method, in a comparison of their own observations with those of the
ancients. This method requires long and laborious calculations; and
continues liable to many doubts, on account of its uncertainty, as
well by reason of the inaccurate nature of the instruments, as of the
observations of the ancients. But this is not the case with my new
method; from which, by means of the variation observed between the
satellite and its brighter fixed star, it necessarily results, that
the appropriate motion, either of the one star or the other, is to be
attributed to it. Hence it is, that, within two years past, I have
observed almost two hundred attendants of divers fixed stars; moving
nearly in the same parallel, immediately before or after their
respective fixed stars: and I have communicated many observations of
this kind to the celebrated English astronomer, Nevil Maskelyne, who
assures me they prove highly acceptable to him.
From amongst many of my observations, I transmit to your illustrious
society a few, by way of specimen; the corresponding observations to
which, I find in the Britannic Celestial History of Flamstead; whence
at the same time it is obvious, that observations of this kind are
eminently useful, for the purpose of discovering the proper motion of
such stars.
[The Table, containing the Observations here referred to, will be
found in the second volume of the Society’s Transactions, annexed to
Mr. Mayer’s communication: he then proceeds thus, referring to that
Table.]
The first and second left-hand column of the following Table are
easily understood, from the title. The third column shews the
difference of right ascension, in mean time, between the star and its
satellite: The attendant, preceding the fixed star, is set down in the
first place, in the table; the attendant, following, is placed after
its fixed star. The fourth column notes the difference between the
fixed star and its attendant, as I have observed it at Manheim. The
letter A denotes, that the attendant is to the southward; letter B
more northward. The following columns contain the observations of the
same star, made by Flamstead.
It appears from the whole of the observations, that, of all the stars,
Arcturus is carried with the greatest celerity, by his own motion,
westward; since the same attendant, which in Flamstead’s time, on the
14th of February, 1690, preceded Arcturus 5″ in time, now enters the
meridian 6″ after him. From the diminished difference also, of
declination between Arcturus and his attendant, it is evident, that
Arcturus progresses annually, by his own appropriate motion, nearly 2″
in a circular course, towards the south. From this it clearly results,
that the declination of the attendant, as observed by me, reduced to
the parallel of Greenwich, produces the same altitude of the Greenwich
pole, as that deduced from Flamstead’s observation; but not so, the
declination of Arcturus, observed at the present day, even with the
aberration and nutation corrected.
A similar investigation may be made, with respect to the other fixed
stars and their attendants; and, from the comparison already begun
with other fixed stars, it may be ascertained whether an appropriate
motion is to be attributed to the fixed star or its attendant, or to
both.
All my observations are made in a meridienal plane with a mural
quadrant, at Manheim, in his Serene Highness the Elector Palatine’s
new Observatory, erected for me: its longitude, East from Greenwich,
is nearly 34′ 6″, in time; its latitude, nearly 49° 27′ 50″.
It will give me very great pleasure, if I shall learn that these
observations of mine do not prove unacceptable to your illustrious
society: to whose goodness I most respectfully commend myself; being
ever the very devoted admirer and humble servant of your illustrious
and celebrated Society.
CHRISTIAN MAYER,
Astronomer to his Serene Highness the Elector
Palatine and Duke of Bavaria.
_Manheim, in Germany, April 24, 1778._
---
_Letter from Mr. Rittenhouse to Professor Mayer of Manheim, in Germany._
_Philadelphia, August 20th. 1779._
Sir,
I am directed by the Philosophical Society to acknowledge your letter
of the 24th of April, 1778, and to return you their thanks for
communicating the Observations it contains, wishing you success in
further prosecuting so curious a Discovery. They likewise embrace this
occasion to replace the volume of their Transactions which shared the
fate of your more valuable papers.
This country having been the seat of war, our meetings have been
interrupted for two years past, and the publication of a second volume
thereby prevented; but as the Society is again revived, and we have
materials for the purpose, it will not be much longer delayed.
You will please to accept, by this conveyance, a discourse delivered
some years ago before the Philosophical Society, which I the rather
present you with, because I, therein, gave my opinion that the fixed
stars afforded the most spacious field for the industry of future
Astronomers, and expressed my hopes that the noblest mysteries would
sometime be unfolded in those immensely distant regions.[A40] Your
excellent discovery has proved that passage to be well founded, and I
shall be happy in hearing farther from you on this subject. It is
unnecessary for me to suggest to you a comparison between the many
Observations you have made, in order to determine whether the several
changes observed will agree with any imagined motion of our system.
Those you have communicated seem to favour such a supposition. I am,
Sir, your most obedient and humble servant.
DAVID RITTENHOUSE, _Vice-President_.
-----
Footnote A40:
See page 320 of the foregoing Memoirs.
-----
---
_Some Remarks of Mr. Rittenhouse, on the famous Problem of
Archimedes._[A41]
-----
Footnote A41:
See page 154 of the foregoing Memoirs.
-----
To the Printers of the Pennsylvania Gazette.
_Philadelphia, Oct. 8th. 1767._
Gentlemen,
In your paper, No. 2017, an ingenious gentleman who signs himself T.
T. has favoured the public with remarks upon that celebrated saying of
the famous Syracusean geometrician: “Give me a place to stand on, and
I will move the Earth.” When these remarks appeared, I was engaged in
matters that would not allow me to pay that attention to them, which
they deserved. The justice, however, due to Archimedes, and the
respect I bear for that truly great man’s memory, oblige me now
(though late) to offer my sentiments upon this interesting subject.
I readily agree with your sensible correspondent, as to the conclusion
he has drawn from the principles whereon he seems to have founded his
calculation, without being at the trouble to examine his numbers. All
that I propose is, to place this grand mechanical problem in another
light, wherein it will appear more feasible.
If a ball of earth, weighing 200 pounds, were left at liberty near the
surface of this globe, it would descend, by its own gravity, about 15
feet in one second of time, and about 20 miles in 80 seconds: And if,
as this gentleman supposes, there are about 2000 trillions of such
balls in the whole Earth,—the Earth, by their mutual attractions, in
80 seconds of time; will move toward the ball 1/1736,000,000,000,000
of an inch; and if the same force were to act continually for 105
years, it would move about one inch. Therefore, the force wherewith a
man acts, when he lifts a weight of 200 pounds, if applied without
intermission for the space of 105 years, is sufficient, without any
machinery, to move the Earth one inch in that time;[A42] and it must,
from the velocity received by that force alone, continue for ever
after to move at the rate of one inch in about 50 years.