Chapter V: Part 5

“This very marine time-piece was confided to my charge, in the year
1786, for the purpose of determining the longitudes of my journey by
land; when, called from London by his Serene Highness the Duke of
Saxe-Gotha,—the patron of all the sciences and liberal arts, but more
especially favouring astronomy,—I returned to Germany; where the
erecting of a complete and splendid Observatory, at Gotha, was placed
under my direction.[88b] I then took with me, by the command of his
Serene Highness, a watch of a smaller size, which he usually carried
in his fob,—called by the English a Pocket-chronometer,—made by a
London artist, Mr. Josiah Emery:[88c] which, being made with the
greatest accuracy and ingenuity, yielded nothing in point of
correctness to the larger nautical time-keepers, as may be seen from
three tables of their movements by the illustrious Count Bruhl, and
also of others, by Dr. Arnold, lately established by authenticated
certificates.

“About the end of the year 1786 and the beginning of 1787, I
accompanied His Serene Highness, in a tour through Germany, France and
Italy. In this journey, the longitudes of several places and
astronomical observatories were determined, from a comparison of the
time of a nautical time-keeper (which was set by the solar mean time
in Dover street, London,) with the mean time of the place; which
appears by the altitudes of the sun, by Hadley’s sextant—those which
we call _corresponding_, or by a comparison with it, as transmitted to
us in observatories, by those astronomers. By the same instruments,
therefore, when I arrived at Gotha, I ascertained the longitude of the
future observatory there, with the greatest care and attention; which
the Duke, going to London a few days after, taking with him his
chronometer, at length fully verified.”

Footnote 88a:

Here is a reference, in the text, to note 89.

Footnote 88b:

Here is a reference, in the text, to note 90.

Footnote 88c:

Here is a reference, in the text, to note 91.

Footnote 89:

Sundry astronomical observations were made by this officer, while a
captain in the British navy, in the years 1757, 8, and 9; which were
reported to the admiralty on the 14th of April, 1760, by Dr. Bradley,
then astronomer-royal. See Dr. Bradley’s letter of that date, to the
Secretary of the Admiralty; published (among other papers) in the year
1770, by order of the board of longitude, at the end of T. Mayer’s
Tables and Method of finding the Longitude; edited by Dr. Maskelyne.

Footnote 90:

The Observatory, a very handsome and respectable one, was constructed
at Gotha in the year 1788, under the auspices of the then reigning
Duke of Saxe-Gotha, a zealous patron of astronomy. It is placed on an
eminence, a league from the city, and is built entirely of hewn stone.
Mr. de Zach, a native of Hungary, an experienced astronomer, was
appointed by the duke its director.

The instruments with which the Gotha Observatory is furnished are
chiefly English, as are those of most of the celebrated European
observatories. Among these, is a transit telescope, by Ramsden; and
Mr. Lalande mentions, in his _Astronomie_ (in the year 1792,) that
there were to be added, two murals of eight feet radius, an entire
circle of eight feet diameter, a great zenith-sector, &c. but that Mr.
Ramsden, who was employed to make them, found great difficulty in
supplying all the demands for instruments, which his great reputation
occasioned.

It is well known, that the first improvements in astronomical
instruments took place in Great-Britain; and both Lalande and de Zach,
as well as other foreign astronomers of eminence, have done ample
justice to the superior ingenuity and skill of the artists of that
country, in this department of mechanism. The ingenious Mr. Edmund
Stone, in his _Supplement to the English Translation of Mr. Bion’s
Construction and Use of Mathematical Instruments_, (published in 1758,
nearly forty years after he translated Mr. Bion’s work into English,)
observes—that, having set about the business (the translating of this
latter work,) he soon perceived that many French instruments were
excelled by some of the English of the same kind, in contrivance; and
that, as to workmanship, he never did see one French instrument so
well framed and divided as some English have been. “For example,” says
Mr. Stone, “Mr. Sutton’s quadrants, made above one hundred years ago,”
(before the middle of the seventeenth century,) “are the finest
divided instruments in the world; and the regularity and exactness of
the vast number of circles drawn upon them, is highly delightful to
behold. The mural quadrant at the Royal Observatory, at Greenwich, far
exceeds that of the Royal Observatory at Paris. Also, the theodolites
of Messrs. Sisson and Heath, the clocks and watches of Messrs. Graham,
Tompion and Quare, the orreries of Mr. Graham and Mr. Wright, and many
more curiously contrived and well executed mathematical instruments
which I could mention, far exceed those of the French, or indeed any
other nation in the world.—The making good mathematical instruments,”
continues Mr. Stone, “is almost peculiar to the English; as well as
their skill in all branches of the mathematics and natural philosophy
has been generally superior to that of other nations.”

Without wishing to derogate from the justly acquired fame of British
artists, for the excellence of their mathematical and astronomical
instruments, M. Rittenhouse’s skill and accuracy, displayed in such as
he made, stand unsurpassed by similar works of their most celebrated
mechanicians: while his profoundness in astronomical science, and his
wonderful ingenuity of invention and contrivance, manifested in the
construction of his Orrery, leave him without a rival, in the two-fold
character of an Astronomer and a Mechanic. The idea of the fine
planetarian machine constructed by Mr. Rowley, under the name of the
Orrery, and supposed to have been invented by Mr. Graham, is said to
have been taken from a very similar machine, of which that eminent
philosopher, Dr. Stephen Hales, had the credit of being the original
contriver. But Mr. Rittenhouse was, incontrovertibly, the Inventor, as
well as the Maker, of that sublimely-conceived and unrivalled machine,
which bears the name of the Rittenhouse-Orrery: and Dr. Morse, in
noticing some of the more prominent productions of scientific
ingenuity and skill, in America, observes, with good reason, that
“every combination of machinery may be expected from a country, a
native son of which,” (referring in a note to “David Rittenhouse, Esq.
of Pennsylvania,”) “reaching this inestimable object in its highest
point, has epitomised the motions of the spheres that roll throughout
the universe.” See Morse’s _American Geography_, first published in
1789.

Footnote 91:

The accuracy of some of the fine pocket-chronometers constructed by
the celebrated artists named by Mr. de Zach, and by some others, such,
for instance, as the one made by Emery for the count de Bruhl,
mentioned in the text, has rendered them, on some occasions, useful
assistants in making astronomical observations on land. Dr.
Rittenhouse occasionally used one for such purposes, many years. It
was an excellent pocket-watch, made by Le Roy of Paris for the late
Matthias Barton, Esq. who was induced to let Dr. Rittenhouse have it.
After his decease, this watch was gratuitously restored to its former
proprietor, by Mrs. Rittenhouse’s desire, and as a testimonial of what
she knew to have been her late husband’s regard for his nephew. Mr. M.
Barton bequeathed it, by his last will, to his brother and physician,
Dr. Benjamin S. Barton.

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This very respectable testimony of an eminent German astronomer affords incontestable proof of the great accuracy, of which nautical chronometers are susceptible, and to which they have actually been brought by some artists of celebrity, mostly English.[92]

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Footnote 92:

The Memoirs of the Royal Academy of Sciences at Paris, for the year
1729, contain an article that furnishes additional evidence of the
extraordinary skill and ingenuity manifested by English artists in the
construction of watches, as well as other pieces of mechanism which
require great accuracy in the workmanship: it forms a pleasant little
narrative in an eulogium on Father Sebastian,[92a] a Carmelite Friar
of singular mechanical ingenuity; and it indicates, at the same time,
that the repeating-watch was invented in England. The story is thus
told:—

“Charles II. roy d’Angleterre, avoit envoyé au feu roi deux Montres à
Repetition; _les premieres qu’on ait vues en France_. Elles ne
pouvoient s’ouvrir que par une secrete précaution des ouvriers
Anglois, pour cacher la nouvelle construction, et s’en assurer
d’autant plus la gloire et le profit. Les montres se dérangérent, et
furent remises entre les mains de M. Martineau, horloger du roi, qui
n’y put travailler faute de les sçavoir ouvrir. Il dit a M. Colbert,
et c’est un trait de courage digne d’etre remarqué, qu’il ne
connoissoit qu’un jeune Carme capable d’ouvrir les montres, ques’il
n’y réussissoit pas, il falloit se resoudre à les renvoyer en
Angleterre. M. Colbert consentit qu’il les donnât au P. Sebastien, qui
les ouvrit assez promptement, et de plus les raccommoda sans sçavoir
qu’ elles étoient au roi, ni combien étoit important par ses
circonstances l’ouvrage dont on l’avoit chargé.”

Footnote 92a:

His baptismal name was _John Truchet_.

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The general use of the common clock ought not to derogate from the ingenuity of an invention of such universal importance in the affairs of human life. The pendulum-clock now in use was brought to some degree of perfection, if not invented, by Huygens,[93] who was one of the first mathematicians and astronomers of the age in which he lived: and the date of this invention is about the middle of the seventeenth century; although Galileo disputed with him the discovery, a few years earlier. Clocks of _some_ kind date their antiquity much higher; some writers pretending to carry their invention back as far as the year 510 of the Christian era. However, on the authority of Conrad Gesner,[94] the honour of inventing the clock, before the application of the pendulum to these machines was made by Huygens, belongs to England: He says, that “Richard Wallingford, an English abbot of St. Albans, who flourished in the year 1326, made a wonderful clock by a most excellent art; the like of which could not be produced in all Europe.”[95] This was forty-six years before Henry de Vic, a German, made his clock for Charles V. king of France; and fifty-six years before the duke of Burgundy ordered one, which sounded the hour, to be carried away from the city of Courtray, in Flanders.

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Footnote 93:

This great man, who was the son of Christian Huygens lord of
Zuylichem, a counsellor of the prince of Orange, was born in the year
1629, at Zuylichem, in the province of Guelderland, the country of the
ancestors of Rittenhouse. Having resided for some time in France, he
quitted that country on account of his religion, in 1684, in
consequence of the revocation of the edict of Nantes. He died in
Holland in 1695, at the age of sixty-six years.

Galileo, who was a native of Florence, lived to the age of
eighty-seven years. He died fifty-three years before Huygens; and
about fourteen before Huygens’s application of the pendulum to clocks,
so as to effect an _isochronal_ regulation of their movements.
Galileo’s use of the pendulum, for the purpose of measuring time,
seems to have been nothing more than the annexation of a short
pendulum to clock-work.

Footnote 94:

This celebrated naturalist and physician, who was styled by Boerhaave,
_Monstrum Eruditionis_, was born at Zurich in 1516: He was, probably,
of the same family as that of the late Solomon Gesner the poet, who
was a native of the same city, and appeared more than two centuries
afterwards. Conrad Gesner was so distinguished a writer, as a
naturalist, that he was called the Pliny of Germany. A splendid
edition of Pliny’s Natural History, under the title of the _Historia
Mundi_ of Caius Plinius Secundus, with a dedication by Erasmus to
Stanislaus Turzo, bishop of Olmutz, was printed at Basil, by Froben,
so early as 1525. This copy of Pliny (which is now very rare) having
been published in the vicinity of Conrad Gesner, during his youth,
that circumstance may have prompted him to direct his attention to
those pursuits in science, which distinguished this learned Swiss.

Footnote 95:

About two centuries after that period when the sciences had begun to
revive and the mechanical arts to flourish, the construction of clocks
appears to have been much improved. And in the reign of Henry VIII. a
stately clock was made by an artist, the initials of whose name are
“N. O.” in the year 1540, and placed in the royal palace at
Hampton-Court. This not only shewed the hour of the day, but an
orrery-part, connected with it, exhibited the motion of the sun
through all the signs of the zodiac, and also of the moon, with other
matters depending on them. A similar one, in the cathedral of Lunden
in Denmark, is mentioned by Heylin: But Martin, in his _Philosophia
Britannica_, speaks of a piece of clock-work in the cathedral of
Strasburg, in Alsace; “in which, besides the clock-part, is the
celestial globe or sphere, with the motions of the sun, moon, planets
and fixed stars, &c.” This was finished in the year 1574, and is
represented as being much superior to a pompous clock at Lyons, in
France, which also has an orrery department.

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Within our own day and a short period of time preceding it, great improvements have been made in the construction of the pendulum-clock,[96] as well as in other descriptions of Chronometers.[97] Mr. Rittenhouse’s early zeal in his practical researches into astronomy, prompted him to desire the greatest possible accuracy in the construction of time-pieces adapted to astronomical purposes; and uniting, as he did, operative skill with a thorough knowledge of the principles upon which their construction depends, he was enabled—impelled by so powerful a motive—to display to the world, by his own manual ingenuity, the near approach to perfection to which the pendulum-chronometer may be brought. Besides his astronomical pursuits, his early employment in ascertaining the limits and fixing the territorial boundaries of Pennsylvania, and of some of the neighbouring states, obliged him to supply himself with chronometers of the greatest possible accuracy: and these were either made by his own hands, or under his immediate inspection by his brother, who, with the aid of his instruction, became an excellent mechanician. One of these fine instruments, bearing on its face the name of _Benjamin Rittenhouse_ as the maker, and the date of the year 1786, is now in the possession of Mr. Norton Prior,[98] of Philadelphia: but that admirable one, the workmanship of which was executed by our Philosopher himself, and which was part of the apparatus of his Philadelphia Observatory, is now placed in the hall of the American Philosophical Society.[99] This is constructed on a greatly improved plan of his own, which improvement was afterwards applied to that now belonging to Mr. Prior; and the latter is the same chronometer, it is believed, that was used by Mr. D. Rittenhouse, in fixing the northern line which divides Pennsylvania from New York, and in establishing the boundary line between the last mentioned state, and Pennsylvania and Massachusetts, respectively, in the years 1786 and 1787.—A description of the principles of his observatory-chronometer here mentioned, together with some account of its mechanism, will be found in the Appendix: the former having been communicated to the writer of these memoirs by the ingenious Robert Patterson, Esq. director of the Mint; and the latter by that able mechanician, Mr. Henry Voight, chief coiner in that institution,—a person who, by reason of his well-known skill as a clock and watch-maker, was employed by Mr. Rittenhouse more than forty years since, in the fabrication of some of his philosophical instruments.

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Footnote 96:

The first pendulum-clock made in England, was in the year 1662, by Mr.
Fromanteel, a Dutchman.

In the library-hall of the Philadelphia Library-Company, is one of the
clocks made by that artist, having this inscription engraven on its
face, “_Johannes Fromanteel, Londini, fecit_;” but without any date.
This clock was a donation to the library-company, in the year 1804, by
Mr. Samuel Hudson, of Philadelphia, whose ancestor purchased it at an
auction in London, after the restoration of king Charles II. The
traditional account of it is, that it belonged, originally, to the
Cromwell family; and, when presented, was said to be one hundred and
forty years old: but it could not have been the property of the
protector, Cromwell, the time of whose death was between three and
four years anterior to Fromanteel’s construction of a pendulum-clock.

Footnote 97:

Besides the testimony of so distinguished an astronomer as Mr. de
Zach, already given, respecting the very great accuracy to which
time-keepers have been brought, the following translation, taken from
what the celebrated Lalande has said in his treatise _Des Horloges
Astronomiques_, (in the second volume of his _Astronomie_,) furnishes
some curious and interesting facts on that subject.

“Short (the mathematical instrument maker,) upon the occasion of the
transit of mercury over the sun observed in 1753, assures us that he
had found by many observations, that his clock had not varied more
than one second, from the 22d of February to the 6th of May (_Philos.
Trans._ 1753, p. 200;) so that, with a like pendulum, it is possible
to obtain an exactness which, till this time, was thought incredible.
There are English astronomers who have assured me,” continues Lalande,
“that pendulum-clocks have been made which did not vary more than
five″ in a year:[97a] but that does not appear to me to be yet
established as a fact; the oils that one is obliged to use in them are
sufficient, by the change of consistency they undergo, to prevent such
preciseness. The count de Bruhl, a great amateur and a perfect
connoisseur also, on the subject of time-pieces, shewed me in London a
diary of the going of two pendulums of Mudge, one of the most
celebrated clock-makers in London: in one, there was a difference of
half a second a day, between winter and summer; and in the other a
second. Mr. Aubert has a pendulum made by Shelton, which varies also
nearly a second in the day, in extreme seasons. Picard, in 1671, had a
clock which did not lose a second in two months. But, whatever may
have been, since that period, the skill of the clock-makers of Paris,
we cannot obtain such exactness, but by mere accident and an equality
of temperature in the atmosphere that is very rare: now, the
correctness of our clocks is a necessary consequence of their
principles; but these do not go so far. Mr. Emery has observed two
clocks beat the same second, during three months; they were, however,
very near to each other, and probably had some influence on one
another by means of their foot-board or support.”

Footnote 97a:

Even watches have been already brought to an inconceivable degree of
exactness. Mr. Arnold and Mr. Emery made some, in the year 1786, which
did not vary one second in a voyage of an hundred leagues.

Footnote 98:

This gentleman’s name is connected with another circumstance in
relation to Mr. D. Rittenhouse, which deserves to be noticed. He is in
possession of a finely-graduated thermometer, made by our Philosopher;
on the scale of which is engraved, by him, the record of a memorable
fact concerning the climate of Pennsylvania, referring by a mark to
22° _below_ 0, of Fahrenheit’s scale; viz.—“_Jan. 2. 1762—Great Cold
in Pennsylvania_.” This fact was ascertained by Mr. Rittenhouse, from
a reference to the accurate Messrs. Masons and Dixon’s Journal; in
which, such was stated to have been the degree of cold in the forks of
the Brandywine (about thirty miles westward, and very little to the
southward, from Philadelphia,) on the day mentioned.

Mr. Rittenhouse had noticed, that, at his Norriton Observatory, (in
lat. 40° 9′ 31″ N.) the mercury in Fahrenheit’s thermometer, not
exposed to the sun-shine but open to the air, was at 94½°, on the 5th
of July 1769; “which,” says he, “was the greatest height it had ever
been observed to rise to, at that place.” But the writer is informed
by a judicious and attentive observer, that at Lancaster,
Pennsylvania, which is in lat. 40° 2′ 39″ N. (the long. of this
borough-town is 5^h 1′ 4″ W. from Greenw.) the mercury rose by
Fahrenheit’s scale, on the 7th of July, 1811, to 97½°. Admitting this
to be correct, if 1½° be then deducted, for the extra heat of so large
a town as Lancaster in comparison with a country-situation, there is
in this case the great range of 118° by Fahrenheit’s scale, for the
extremes of heat and cold in Pennsylvania.

The writer brought with him, from England, a meteorological diary kept
in London, during the severe frost there, from the 7th day of January,
1776, to the 28th of the same month, both days inclusive. The greatest
cold, during that period, was 15° and it is thus noted, in respect to
the state of the atmosphere at the time; “Clear sky—_intense
cold_—wind west.” The mercury rose on one day, within that time, to
34°. The _mean_ degree of cold, in the same period, was there 26¾°.

The greatest cold at Philadelphia, during the same days of January,
1776, was at 17°, but the mercury rose there, on one of those days, to
48°. The _mean_ degree of cold at Philadelphia, in this corresponding
period of time, was 29⅓°; being about 2½° warmer (or rather, less
cold,) than the general temperature of the weather in London, at the
same time, in what was there called a “severe frost.” Eighty-five
degrees of Fahrenheit’s scale is considered as a very extraordinary
heat, in London: consequently, a range of 68° may be presumed to reach
the extremes of heat and cold in England, in the latitude of nearly
52° N.[98a]

Notwithstanding the extremes of heat and cold, which thus appear in
the climate of Pennsylvania, Mr. Jefferson remarks (in his _Notes on
Virginia_,) that these extremes are greater at Paris than at
Williamsburg, the hottest part of Virginia. Yet Williamsburg, which is
only about 2¾° to the southward of Philadelphia, is nearly 11¾°
further south than Paris.

Footnote 98a:

Since writing the above, the author has ascertained, that in London,
during the four last years of the last century, Six’s thermometer, out
of doors, averaged 49.6; that on the hottest day within that period,
the mercury rose to 86; and that it fell, on the coldest day, to 4.

Footnote 99:

See a description of this Chronometer, in the Appendix.

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The great accuracy and exquisite workmanship displayed in every thing belonging to the profession he pursued, that came through his hands, soon became pretty extensively known: and this knowledge of his mechanical abilities, assisted by the reputation he had already acquired as a mathematician and astronomer, in a short time procured him the friendship, respect and patronage, of some eminent scientific characters; while it promoted his interest, in the profession he had thus newly chosen. In this he was, nevertheless, _self-taught_; for he never received the least instruction from any person, in any mechanic art whatever: and, therefore, if he were to be considered as being merely an excellent artist, in an occupation intimately connected with the science of mathematics—_untutored_, as he was, in any art or science,—he would deservedly be deemed an extraordinary and eminent man. It will be perceived, however, that it was the _union_ of the almost unbounded powers of his genius, and his prodigious acquirements in a sublime science, with his wonderful abilities as a philosophical mechanic—and these faculties and attainments, moreover, combined with an amiable and virtuous character,—which constituted that celebrity so justly attached to his name.

Our young philosopher lived a retired, though by no means an inactive life, in his father’s family, for several years after he arrived to (what is usually termed) lawful age. In this situation, which was a pleasant one in many respects, he long continued to enjoy the tranquil scenes of rural life, amidst the society of an amiable and very intelligent family-circle, and surrounded by many worthy and estimable neighbours, by whom he was both loved and respected. His chief occupation was the profession he had chosen; but in such occasional intervals of personal abstraction from the mechanical part of his business, as the assistance the workmen he employed enabled him to obtain, he devoted much of the time to philosophical pursuits and study. Frugal in his expenditures, his industry furnished him amply with the means of comfort; and in the plentiful and decent mansion of his father’s family he experienced, with contentment, almost every gratification that a reasonable mind could desire. Good health seemed alone to be wanting to complete his happiness, in his earlier years; a privation which he felt through the greater part of his life.

Such was the condition of Mr. Rittenhouse, while he remained under the same roof with his father and mother, and some of their unmarried children. It was a mode of life which his disposition was calculated to enjoy; for, strongly attached to his kindred and friends by the benevolence of his nature, he derived much of his happiness from the reciprocal affections of a domestic circle and the kind intercourses of friendly esteem.

There does not appear to have been, for a long time, any occurrence that could have much disturbed the placid composure of our philosopher’s mind,—until 1762; in which year his sister Anne died, in the twenty-sixth year of her age. She was the wife of Mr. George Shoemaker, a respectable citizen of Philadelphia, and a member of the religious society of Friends. A letter which Mr. Rittenhouse wrote to his brother-in-law Mr. Barton, in October 1762, announcing this event, indicates the keenness of his sensibility on the occasion. Mrs. Shoemaker was a woman of intrinsic worth; she died in the prime of life; and it is believed, she was the first of Mr. Rittenhouse’s affectionate little band of brothers and sisters who had attained to the age of maturity, that he had then lost. After giving a circumstantial account of his sister’s illness and death, he informs Mr. Barton, that Mr. Daniel Stanton, an eminent public speaker in the society of Friends,[100] attended her in her last illness, at her particular request;—and, added Mr. Rittenhouse, “the same worthy gentleman who visited her in her sickness, delivered an excellent exhortation at the grave,—giving, in a few words, a very just character, I think, of our deceased sister.”

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Footnote 100:

Mr. Stanton died at Philadelphia, the 28th of June, 1770, aged
sixty-two years. He was, for above forty years, a distinguished
preacher among the people called Quakers; and is reputed to have been
a man, “who, from his youth, had been a conspicuous example of
Christian meekness, humility, and self-denial; a zealous promoter of
the cause of religion, and the essential good of mankind.”

Some elegiac verses, under the title of a “poetic tribute” to
the memory of this worthy man,—from the pen of a lady in
Philadelphia,—were published in the _Port Folio_, for April
1813.

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Mr. Shoemaker (who married again) had an only child named Jacob, by his first wife here mentioned. This son became a young man of promising character: but, having entered the American army at the commencement of the revolutionary war, and attained (it is believed) the rank of captain, under the patronage of his uncle David Rittenhouse, he was slain in the campaign of 1781, in South-Carolina. Mr. Rittenhouse was much afflicted by the death of this gallant young man, who fell in the flower of his age.

An occasion presented itself, in which Mr. Rittenhouse, when only in the thirty-second year of his age, was employed in transacting an important piece of business of a _public_ nature: it was as follows.

In consequence of a petition of the Messrs. Penn to the court of chancery in England, exhibited in the year 1735, it was decreed by the lord chancellor, in 1750,—That an agreement which had been entered into between the Penns and Lord Baltimore, concerning the long-subsisting controversy relative to the boundary lines between Pennsylvania and Maryland, should be carried into specific execution: and, accordingly, a final agreement was executed by those proprietaries of the two provinces, on the fourth day July, 1760.

In pursuance of the chancellor’s decree, provision was made for ascertaining and fixing the “circle,” to be “drawn at twelve miles distance from New-Castle, northward and westward, unto the beginning of the fortieth degree of north latitude;”—and thence, running a straight line westward, five degrees in longitude, to be computed from the eastern boundary; as described in the royal charter to William Penn. Commissioners were appointed under the chancery-degree, for settling these boundaries. But nothing was definitively done in the business, until the eleventh of January, 1769; when the line which was run by Messrs. Mason and Dixon in the years 1767 and 1768, in pursuance of the final agreement between the parties before mentioned, was approved and ratified by the king in council.

So early, however, as about the close of the year 1763, four or five years before the running and marking of Mason and Dixon’s line, Mr. Rittenhouse was employed by the Penn family in making some geographical arrangements, preparatory to the final establishment of those boundaries. He was engaged to perform this service, by the Rev. Mr. Richard Peters, (afterwards D. D. and rector of the united churches of Christ-Church and St. Peters, in Philadelphia,) who then officiated as the Governor’s provincial secretary; a gentleman of learning and great worth; and one who, on various occasions, manifested a friendship for Mr. Rittenhouse, as well the high opinion he entertained of his abilities.

The particular department of that business thus committed to Mr. Rittenhouse, seems to have been the fixing of _the Circle_,—or at least, the tracing of its course or route, topographically; and this was, certainly, a matter of no little difficulty. That this service was performed to the satisfaction of the then administrators of the government of Pennsylvania, and that it was an arduous one, will appear by the following extract of a letter from Mr. Rittenhouse to the Rev. Mr. Barton, dated the sixteenth of February, 1764.[101]

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Footnote 101:

This letter contains, likewise, a short narrative of an occurrence
which excited much feeling, and claimed a considerable portion of the
public attention, at the time. As Mr. Rittenhouse’s account of the
transaction referred to, will serve to shew that he was not an
indifferent spectator of the political events of that early day; and,
further, that he was zealously disposed to support the legitimate
authority of the government, in order to suppress illegal and
disorderly proceedings, subversive of the laws and dangerous to the
public peace and safety; this part of his letter to Mr. Barton (of the
16th of February, 1764,) is also presented to the reader.

It will be recollected that what was called the _Paxton Riot_ in
Pennsylvania, in the year 1763, was occasioned by an attempt made by
many of the inhabitants of a district in the upper end of Lancaster
(now Dauphin) county, called Paxton, with some of their neighbours, to
destroy a number of Indians resident in and near that county; who were
extremely obnoxious to the Paxton people, by reason of the supposed
treachery, if not actual hostility, of these Indians to the settlers
on the Paxton frontier, in the war that had then recently terminated.
These unfortunate Indians had, nevertheless, uniformly professed
themselves to be friendly to the English, in that war; and were so
reputed by the government of Pennsylvania: but finding themselves,
notwithstanding, threatened with extermination by “_the Paxton Boys_”
(as they were then called,)—by whom a few old men, women, and children
had been destroyed, shortly before, at their homes,—they sought the
protection of the government. Part of them were, accordingly, placed
in the public prison in Lancaster, and the remainder at the barracks
in Philadelphia, as places of security. Those in Lancaster, to the
number of fourteen or fifteen, were soon after, as is well known,
killed by the Paxton people, one of the prison doors having been
forcibly broken open by them. The remnant of these persecuted Indians,
who were in Philadelphia, were more fortunate than their brethren;
they escaped the horrors of assassination: And it is to the expedition
against these wretched fugitives—a mere handful of men, unarmed, and
claiming from Christians an asylum from massacre,—that Mr. Rittenhouse
refers in his letter.

“You are no doubt, long before this time, well acquainted,” said our
young philosopher, “with every particular of the Paxtonian expedition
to Philadelphia: nor need I tell you, that whatever information you
may have through the channel of ——, will be abominably corrupt. About
fifty of the scoundrels marched by my work-shop—I have seen hundreds
of Indians travelling the country, and can with truth affirm, that the
behaviour of these fellows was ten times more savage and brutal than
theirs. Frightening women, by running the muzzles of their guns
through windows, swearing and hallooing; attacking men without the
least provocation; dragging them by the hair to the ground, and
pretending to scalp them; shooting a number of dogs and fowls;—these
are some of their exploits.

“I received a letter from sister E. soon after the alarm at
Philadelphia was over, and will give you a part of it, which I doubt
not will be agreeable to you.”—It is as follows.

—“On Monday morning between one and two o’clock, an express came to
the governor, informing that the rebels were on their way, and that a
great number of them were on this side the White Horse. There was one
express after another, till there was certain intelligence that some
of them were at Germantown. When the first express came, the bells
were rung, the drums beat, and the constables were ordered to go from
house to house, to knock up the inhabitants, and to bid them put
candles at their doors: it had the appearance of all the houses being
illuminated. Before day, there were above twenty men met at J. J.’s,
and chose their officers. Before night they were increased to nearly
an hundred; as were likewise most of the other companies: E—— and all
our men were in captain Wood’s company. They all appeared to be in
high spirits, and desirous to meet the rebels. On Tuesday, when the
mayor and the other gentlemen set off for Germantown, the heads of the
companies begged of them not to comply with any dishonourable terms,
and told them—“Gentlemen, we are ready to go wherever you may command
us; and we had much rather you would let us treat with them (the
rebels) with our guns.”—On their return, there was a general murmur
among the companies against the proceedings of our great men; they
knew it, and there was a long harangue made by Mr. Chew: but it did
not answer the end. On Wednesday morning I went to —-—, as usual; and
on my return home, I stopped at our friend H. J.’s; when, on a sudden,
the alarm-gun was fired, the bells began to ring, and the men called
“_to arms_,” as loud as possible. I cannot describe, my dear brother,
how I felt: we ran to the door, when to add to my fright, I saw E——,
amidst hundreds of others, run by with his gun. They met at the
court-house, formed themselves into regular companies, and marched up
Second-street as far as the barracks; when they found it was a false
alarm.

“It was a pleasing, though melancholy sight, to view the activity of
our men. In less than a quarter of an hour, they were all on their
march,—it is supposed above a thousand of them; and by all accounts,
there were not ten —— among them. It was the common cry, while our men
were parading—“What! not one —— among us!”—Instead of joining with
others, they would sneak into corners, and applaud the “Paxton-boys.”
Their behaviour on this occasion has made them appear blacker than
ever.”

Concerning these extraordinary transactions, to which much importance
was attached in their day, and which, moreover, constitute a curious
and interesting occurrence in the history of Pennsylvania, in the time
of our philosopher, the testimony of another respectable witness is
added; a person, besides, who bore a principal part in arresting the
progress of the insurrection referred to. On the 2d of June, 1765, Dr.
Franklin, who was then in London, wrote a letter to the celebrated
Henry Home, lord Kames, in which the following interesting
circumstances are related, respecting what was called the Paxton
Expedition: this letter is inserted entire in lord Woolhousie’s
_Memoirs of the Life and Writings of Lord Kames_. The Doctor therein
says—“In December (1763,) we had two insurrections of the back
inhabitants of our province, by whom twenty poor Indians were
murdered, that had from the first settlement of the province lived
among us, under the protection of our government. This gave me a good
deal of employment; for, as the rioters threatened further mischief,
and their actions seemed to be approved by an increasing party, I
wrote a pamphlet, entitled _A Narrative_, &c. to strengthen the hands
of our weak government, by rendering the proceedings of the rioters
unpopular and odious. This had a good effect: and afterwards, when a
great body of them with arms marched towards the capital in defiance
of the government, with an avowed resolution to put to death one
hundred and forty Indian converts, then under its protection, I formed
an association at the governor’s request, for his and their defence,
we having no militia. Near one thousand of the citizens accordingly
took arms: Governor Penn made my house for some time his
head-quarters, and did every thing by my advice; so that, for about
forty-eight hours, I was a very great man, as I had been once some
years before, in a time of public danger. But the fighting face we put
on, and the reasonings we used with the insurgents, (for I went, at
the request of the governor and council, with three others, to meet
and discourse them,) having turned them back, and restored quiet to
the city, I became a less man than ever; for I had, by these
transactions, made myself many enemies among the populace.”

-----

“I hope,” said he, “you will never believe that I am determined to disclaim all kind of intercourse” with you: for I can say with the greatest sincerity there are very few things I so much regret, as that I have it not in my power to spend a great part of my time with you. My attention has, for some time past, been engaged with such a multiplicity of things, that I may with some reason claim your indulgence for my not writing. Have I not, indeed, an equal right to complain?—for, I think this letter will balance our accounts, from the time I last saw you.

“I waited on Mr. Peters, as you desired me to do. He treated me kindly, and made an offer of doing me some services; for which I am greatly obliged to him. He likewise paid me for my attendance at New-Castle, and much more generously than I expected;—though I found it a very laborious affair; being obliged, singly, to go through a number of tedious and intricate calculations.”

It appears that about this time, Mr. Rittenhouse’s friends had some beneficial object in view for him; perhaps some official situation, which they conceived to be adapted to the nature of his pursuits, and such as might more permanently promote his interests. But whatever that object may have been, he seems to have hesitated about it. If it were a public appointment of a permanent kind, it would probably have required his removal to the city,—a measure which he did not contemplate at that time; and he might, besides, have been disinclined to undertake any official duties, which would be likely to occupy the greater part of his time. He expressed himself thus to Mr. Barton, on the subject, in the letter just quoted:—“I am greatly obliged to you, my dear brother, for pointing out any prospect of advantage to me: I shall consider the matter you mention in your last, and let you know my opinion. The objections you have so well answered, are those which would most readily occur to me. Considering the crazy state of my constitution, a retired life would certainly suit me best. Since death, to use John Bunyan’s[102] phrase, does usually knock at my door once a day, would it not be a folly for me to take up the load of any public business?”

Footnote 102:

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The writer of these memoirs well remembers to have heard Mr.
Rittenhouse, when fully matured in years, speak of the pleasure he
derived from the reading of John Bunyan’s _Pilgrim’s Progress_, while
a youth. It is, certainly, no faint compliment to the “well-told tale”
of that “ingenious dreamer,” that it engaged the attention of David
Rittenhouse, even at a very early period of his life: and that
compliment is greatly enhanced by the following beautiful invocation,
addressed to the long-since departed spirit of the humble, yet
persecuted, the pious, yet fanciful Bunyan, by the amiable Cowper:—

“Oh thou, whom, borne on fancy’s eager wing,
Back to the season of life’s happy spring,
I pleas’d remember, and, while mem’ry yet
Holds fast her office here, can ne’er forget;
Ingenious dreamer, in whose well-told tale
Sweet fiction and sweet truth alike prevail;
Whose hum’rous vein, strong sense, and simple style;
Witty, and well-employ’d, and, like thy Lord,
Speaking in parables his slighted word;
I name thee not, lest so despis’d a name
Should move a sneer at thy deserved fame:
Yet, ev’n in transitory life’s late day,
That mingles all my brown with sober gray,
Revere the man, whose PILGRIM marks the road,
And guides the PROGRESS of the soul to God.”
Cowper’s _Tirocinium_.

The celebrated Benjamin Franklin too, in the account of his Life
written by himself, informs us, that the _Pilgrim’s Progress_ (which
Franklin there, inadvertently, calls “_Bunyan’s Voyages_,”) was a
favourite book of his, in his earlier years. “I have since learned,”
says the Doctor, “that it has been translated into almost all the
languages of Europe; and, next to the Bible, I am persuaded, it is one
of the books which has had the greatest spread.”

-----

About three years afterwards, Mr. Rittenhouse seemed to have been less indisposed to accept of an official situation: and, such was his high standing with the government and its most influential friends, there can be very little doubt he could have obtained a respectable one. It is evident that, at this latter period, when perhaps his health was improved, he had some particular office in view: because, by a letter to Mr. Barton, dated January 28th 1767, he said—“I am entirely satisfied with your proceedings in the affair I recommended to you; and I shall wait on Mr. Peters. The reputation of the office would be very agreeable to me; but the execution of it would, I am afraid, greatly interfere with the other projects you have so much insisted on.”

Mr. Rittenhouse continued a bachelor until the 20th of February, 1766, when he married Eleanor Colston, daughter of Bernard Colston, a reputable farmer in the neighbourhood. This person belonged to the religious society called Quakers; Mr. Rittenhouse was not himself a member of any particular church: but the marriage was solemnized at Norriton, by the Rev. Mr. Barton, who went thither for the purpose at his brother-in-law’s request.

Some time prior to this event, old Mr. Rittenhouse, having previously made his son David the proprietor of the Norriton farm, removed with his family to the house he had built[103] on his place in Worcester township, already mentioned; while the son’s family occupied the old place of residence: and here our Astronomer remained about four years after his marriage. It was during this period, that his reputation as an astronomer became eminently conspicuous;[104] his name acquired a celebrity even in the old world, of which his early but now much increased fame, in his native country, was a sure presage.[105]

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Footnote 103:

This was about the year 1764.

Footnote 104:

In the earlier part of this interval of time, and before he became
more seriously engaged in those great works and researches, the
construction of his Orrery, and the Observation of the Transit of
Venus with the operations preparatory to it, which about that time
engrossed his attention, he occasionally amused himself with matters
rather speculative than practical: though he very seldom devoted any
considerable portion of his time to things which he did not consider
as being in some degree useful.

The following is one of those instances in which his active mind was
diverted from severer studies, to some objects of a more playful
nature.

In the year 1767, some ingenious country-gentleman published in
Messrs. Hall and Sellers’s paper, under the signature of T.T. the
result of calculations he had made on Archimedes’s famous vaunting
assertion, Δος που στω, και την γην κινησω. Mr. Rittenhouse published,
some short time after, calculations (or rather the result of
calculations) of his own, on the same problem. This appeared in a
piece under the signature of “_A Mechanic_,” dated the 8th of October,
1767: and a reply to it, by T. T. dated October the 29th, appeared in
the same paper. These little speculations will be found in the
Appendix. It is not improbable that Mr. Rittenhouse, under the
disguise of “A Mechanic,” appeared in print on this occasion, for the
purpose of drawing the attention of ingenious men to subjects of this
nature.

Footnote 105:

It was between the years 1766 and 1770—the interval of time above
mentioned,—that the two important circumstances occurred, which gave
great celebrity to the reputation of Mr. Rittenhouse, as an
astronomer: these were the Construction of the Orrery invented by him,
and the admirable result of his observations of the Transit of Venus,
as published in the Philosophical Society’s Transactions.

Amidst those objects of importance in which he was principally
occupied, he occasionally amused himself with matters of minor
consequence. Among other things, he contrived and made, in the
beginning of the year 1767, an ingeniously contrived thermometer,
constructed on the principle of the expansion and contraction of
metals, by heat and cold, respectively. This instrument had, under
glass, a face upon which was a graduated semi-circle: the degrees of
heat and cold corresponded with those of Fahrenheit’s thermometer; and
these were also correspondently designated, by an index, moving on the
centre of the arch. Its square (or rather parallelogramical) form, its
flatness and thinness, and its small size—together with its not being
liable to the least sensible injury or irregularity, from any position
in which it might be placed,—rendered it safely portable; insomuch,
that it could be conveniently carried in the pocket.

He presented one of these metaline Thermometers to Dr. Peters, in June
1767: Another, which he made for himself, was a considerable time in
the hands of Mr. Barton, at Lancaster. They were found to agree very
well with Fahrenheit’s. In a letter to Mr. Barton, dated the 26th of
July 1769, he said—“You will oblige me by sending the metaline
thermometer by..., and let me know the greatest height you have seen
it, this season, Fahrenheit’s thermometer, in my Observatory, not
exposed to the sunshine but very open to the air, was 94½° on the 5th
of this month, at 3 in the afternoon; which is the highest I have ever
seen it.”

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About the time that he projected his Orrery (which shall be duly noticed in its place), it appears he had been speculating on the doctrine of the compressibility of water. For in a letter to Mr. Barton, dated from Philadelphia the 27th of March, 1767, he mentions,—that he had not then met with any person, who had seen Mr. Kinnersley’s[106] experiment on that theory; but that he understood it was made with the air-pump, and conjectured it to have been similar to the one made by a member of the Royal Society, related in Martin’s Magazine: which is thus quoted in Mr. Rittenhouse’s letter:

“I took a glass ball of about an inch and 6/10 in diameter, which was joined to a cylindrical tube of 4 inches and 2/10 in length, and in diameter 1/100 of an inch; and by weighing the quantity of mercury that exactly filled the ball, and also the quantity that filled the tube, I found that the mercury in 23/100 of an inch of the tube was the 10000th part of that contained in the ball; and with the edge of a file, I divided the tube accordingly. This having been done, I filled the ball and part of the tube with water exhausted of air: Now, by placing this ball and tube under the receiver of an air-pump, I could see the degree of expansion of the water, answering to any degree of rarefaction of the air; and by putting it into a glass receiver of a condensing engine, I could see the degree of compression of the water, answering to any degree of condensation of the air, &c.”—Then adds. Mr. Rittenhouse—“Indeed I do not doubt the compressibility of water, although the above experiment does not much please me. If the particles of water were in actual contact, it would be difficult to conceive how any body could much exceed it in specific gravity; yet we find that gold does, more than eighteen times.”

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Footnote 106:

The Rev. Ebenezer Kinnersley, A. M. Professor of English and Oratory
in the college of Philadelphia. This venerable and worthy man, who was
a clergyman of the Baptist church, was a very eminent Electrician. In
this branch of philosophy, he was an able lecturer and ingenious
experimentalist: and perhaps to no person—at least in America,—were
his cotemporaries more indebted, than to him, for the light which he
shed, at a very early day, on this interesting and pleasing science.

-----

The first academic honour conferred upon our philosopher, was on the 17th of November, 1767; when the College of Philadelphia, then in its meridian splendour, bestowed on him an honorary degree of Master of Arts. Mr. Rittenhouse being present at the commencement then held, the provost, in conferring this degree, thus addressed him,—in terms of a just and well merited compliment:

“Sir,—The trustees of this College (the faculty of professors cheerfully concurring), being ever desirous to distinguish real merit, especially in the natives of this province,—and well-assured of the extraordinary progress and improvement which you have made, by a felicity of natural genius, in mechanics, mathematics, astronomy, and other liberal arts and sciences, all which you have adorned by singular modesty and irreproachable morals,—have authorized and required me to admit you to the honorary degree of Master of Arts, in this seminary: I de therefore, by virtue of this authority, most cheerfully admit, &c.”

Mr. Rittenhouse’s great abilities, as an astronomer and mathematician, being now every where known, he was employed in the year 1769, in settling the limits between the provinces of New-York and New-Jersey. The original grant of all the territory, called by the Dutch _New-Netherlands_ (sometimes _Nova-Belgia_), was made by King Charles II. to James Duke of York, on the 12th of March, 1663-4; and on the 24th of June following, the Duke granted that part of it, now called New-Jersey, to the Lord Berkeley of Stratton and Sir George Carteret, jointly. The Dutch reduced the country, in the year 1672; but it was restored by the peace of Westminster, February the 9th, 1673-4. On the 29th of June, in the same year, a new patent was issued to the Duke of York, for the lands comprised within the limits described in the former patent. On the 28th of the succeeding July, the colony of New-Jersey was divided into East and West-Jersey (hence, generally called the Jersies); and the former was then granted, by the Duke of York, to Sir George Carteret. In 1675, West-Jersey, being Lord Berkeley’s moiety of the province, was sold to John Fenwick, in trust for Edward Bylinge; who assigned his interest therein to William Penn and others,[107] in trust, for the use of his creditors. This partition was confirmed in the year 1719, by the general assembly of the Jersies. But prior to this confirmation, viz. the 10th of October, 1678, a new grant of West-Jersey was made by the Duke of York, to the assigns of Lord Berkeley; and on the 1st of February, 1681-2, East-Jersey was sold and conveyed, in pursuance of Sir George Carteret’s will, to twelve persons; who, by separate deeds, conveyed one-half of their several interests in the same to twelve other persons: and, on the 14th of the next month, the Duke of York made a new grant of East-Jersey to those twenty-four proprietors, thereby confirming the same to them. The proprietors of both the Jersies afterwards became very numerous, by purchase as well as by descent. This being attended with great inconveniencies, they finally surrendered the government to the crown, on the 17th of April, 1702: and from that time, the province of New-Jersey continued to be a royal government, until the American revolution.

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Footnote 107: