Thomas Jefferson Papers
Note: this document has content that may require expanded/print view for best results (icons above right)

From Thomas Jefferson to Bishop James Madison, 4 March 1798

To Bishop James Madison

Philadelphia Mar. 4. 98

Dear Sir

A person here imagines he has discovered a new property […] [magne]tic needle, which however, for want of a well-made dipping needle, he can[…] at least to my satisfaction. there is no such instrument at this plac[e. I] think I recollect to have [seen a] very fine one at your college. I must the[refore] take the liberty of solliciting you to make an experiment for us, which […] the less unwillingness as it is only an experiment of a single instant. […] the meridian of the needle, so that the North end shall be to the South, […] South end to the North, & mark it’s dip with accuracy while in that posit[ion.] […] not certain that I recollect exactly the construction of the instrument, but […] it hung on a cross-axis, & had a brass meridian in the plain of the needle, […] was graduated on the inner edge so as to indicate the dip of the needle or [decli]nation from the horizontal level. however whatever be it’s construction […] have no difficulty in managing it according to it’s construction so as to […] declination of the needle below the horizontal level when it’s ends are in […] of the plain [but] […]. repeat the experiment if you please several […] we may be [satisfied] whether the result be uniform & what it is. the […] is poor, & expects to make some thing by his discovery, if it be real. I am […] not at liberty [to say to] you what it is; but on the contrary have to […] [may] […] about it till you hear further from me, which […] experiments result.

[…] a Professor Zach, Director of the Observatory […] [Patterson] of the Philosophical society, giving us some ob[…] […] that Mr. Schroter, astronomer at Lilienthal near […] Hanover, with a […] [feet] refrac[tor], has [disc]overed a spot in two of Jupit[er’s moons?] by which [he has been able to] observe the ro[tation] of these satellites on their ax[es.] that each [revolves] on it’s axis exactly within the same time as round it’s pla[net] […] [planetary rotation] […], of which before we had no knowlege. […] of our […] be general to […] secondaries.1—de Zach has noted an error in mr Ellicot’s observation of the Polar star. he states it’s true position as follows.

AR. media Polaris. Var. ann. Declin. media Var. ann.
  °   ′  ″  ′  ″   °   ′   ″   ″
1796. 12-[52–58.90] 3– 10.45 88–13–  5.73 19.[516]
1797. 12– 56–  8.35 3–  11.46 88–13–[25.25] 19.[512]
1798. 12– 59–18.80 3– 12.51 88–13– 44.77 19.[508]
1799. 13–  2-30.26 3–[13.57] 88–14–  4.28 19.[504]
1800. 13–  5-42.77 88–14– 23.79

he observes that three observations in 1795 at Blenheim, London & Palermo made it’s expolarity to be

  •   °   ′   ″
  • 147–13.770
  • [l-]47–13.[688]
  • 147–13.[790]

so that there is now not the single second’s incertitude about it.—he has calculated the longitude of Philadelphia from mr Rittenhouse’s observation of the annual eclipse of the sun Apr. 3. 91. and makes it 5H—10′—3″. Euler by observation of the transit of ♀ had made it 5H—10′—6″. he concludes therefore that Dr. Ewen2 had made it too small by the eclipses of Jupiter’s satellites.

We had before had all our chemistry to learn over again, and also our calendaring time revolutionized. we have now to learn a new system of geography, if the partition of Europe in the papers of the day be authentic. […] ourselves had set the example of reformation in the principles of politics: so that all our old books are becoming like old almanacs, and science itself like the shifting phantasms of the magic lanthern. we have nothing yet from our envoys at Paris. their silence however most certainly is an evidence of peace. I hope we shall be able to rub through the present war, without entering into it: and that during the next interval of peace our rulers will have the […], & our people the self-denial, to establish such a system of commercial regulation as shall […] any injustice of any nation towards our commerce or navigation react on itself as regularly as effect [follows] cause &3 […] and […] entirely peaceable. the peculiar character of our commerce […] them in our power as to this, and tho it would bring on our farmers temp[orary] […], these [would] be nothing in comparison with the evils of war.   Congress […] [any] thing to do. the moment we hear from our envoys, if the […] we may all go home. an awful crisis [seems] impending over Great Britain. it is indeed a conflict of chances, but all the chances are not [on one side]: the issue therefore is in dubio. accept my salutations & assurances of friendly esteem & respect.

Th: Jefferson

PrC (DLC); at foot of first page: “Bishop Madison”; faint, torn along margin of first page, several phrases illegible; figures in brackets supplied from TJ’s notes on Zach’s letter (see below).

Person here: see TJ to Andrew Gwin, 24 Mch. 1798.

Franz Xavier von zach, an astronomer whose observatory near Gotha was under the patronage of the Duke of Saxe-Coburg, had sent some of his published works to the American Philosophical Society, which acknowledged receipt of the books at a meeting of 17 Nov. 1797. TJ did not attend that meeting but presided over another on 19 Jan. 1798 at which Zach, an active disseminator of astronomical data who regularly exchanged information with American scientists, was elected to membership (DSB description begins Charles C. Gillispie, ed., Dictionary of Scientific Biography, New York, 1970–80, 16 vols. description ends , 14:583; APS description begins American Philosophical Society description ends , Proceedings, 22, pt. 3 [1884], 262, 266; Greene, American Science description begins John C. Greene, American Science in the Age of Jefferson, Ames, Iowa, 1984 description ends , 135, 142, 154–5). Robert Patterson, who in 1797–1798 was a curator of the society and had recently served as one of its secretaries, was the recipient of a letter from Zach that has not been found but evidently accompanied the books sent by the German astronomer (APS description begins American Philosophical Society description ends , Proceedings, 22, pt. 3 [1884], 235, 246, 266). TJ made notes on “de Zach’s Ire to mr Patterson” but did not record its date. The notes include the table of the right ascension and declination of Polaris and the other data from Zach that TJ reported to Bishop Madison in the letter above. TJ identified Zach as “Director of the Observatory at Seebourg in Saxony” (MS in DLC: TJ Papers, 232:41533; entirely in TJ’s hand; undated; endorsed: “Astronomy”; see notes 1–2 below).

The observatory at lilienthal, overseen by Johann Hieronymus Schroter, held some of the finest equipment in Europe and was a center for astronomical research (DSB description begins Charles C. Gillispie, ed., Dictionary of Scientific Biography, New York, 1970–80, 16 vols. description ends , 12:226). Zach publicized Schröter’s recent discovery in Allgemeine Geographische Ephemeriden, Verfasst von einer Gesellschaft Gelehrten und herausgegeben von F. Von Zach, H.S.G. Obristwachtmeister und Direktor der herzoglichen Sternewarte Seeberg bey Gotha, 1 [1798], 131–3, XVI-XVII.

Observation of the polar star: Andrew Ellicott had published tables and other data on the position of Polaris in APS description begins American Philosophical Society description ends , Transactions, 3 [1793], 116–18, and as a pamphlet, Several Methods by Which Meridional Lines May be Found with Ease and Accuracy: Recommended to the Attention of the Surveyors in the United States (Philadelphia, 1796). See Evans, description begins Charles Evans, Clifford K. Shipton, and Roger P. Bristol, comps., American Bibliography: A Chronological Dictionary of all Books, Pamphlets and Periodical Publications Printed in the United States of America from … 1639 … to … 1820, Chicago and Worcester, Mass., 1903–59, 14 vols. description ends No. 30385. By declaring that the table in the above letter represented the true position of the pole star, TJ probably meant that Zach’s figures were more accurate than earlier data, not that the table took into account all variables affecting the star’s apparent location in the sky, such as aberration and nutation. Zach’s great compendium of star tables, the Tabulae Speciales Aberrationis et Nutationis, was not formally published until 1806, but portions were printed earlier. Apparently one of those incomplete versions was the work that the American Philosophical Society received from Zach in November 1797. Zach continually refined his data, and the figures for the pole star in the 1806 edition do not precisely match those in the letter above (Zach, Tabulae Speciales Aberrationis et Nutationis in Ascensionem Rectam et in Declinationem …, 2 vols. [Gotha, 1806], 1:76; Connaissance des Tems, Year 8 [1799–1800], 400; Year 10 [1801–1802], 326).

For his 1770 calculation of the longitude of Philadelphia, expressed in the letter above as hours, minutes, and seconds west of the meridian of the Paris Observatory, the renowned European mathematician and scientist Leonhard euler drew on data from the transit of Venus between the earth and the sun in June 1769. Euler collected other calculations of the city’s longitude as well, including one of 5 hours, 9 minutes, and 55 seconds west of Paris that had been derived using observations of the movements of Jupiter’s satellites and was reported to the APS description begins American Philosophical Society description ends in 1769 by Presbyterian minister and avid astronomer John Ewing, who long served as provost of the University of Pennsylvania. Bishop Madison and Ewing had been contentious rivals in 1784, when they represented Virginia and Pennsylvania respectively on a commission fixing the boundary between the two states (Leonhardi Euleri Opera Omnia [Leipzig and Berlin, 1911], ser. 2, vol. 30:153, 225–6; APS description begins American Philosophical Society description ends , Transactions, 1 [1771], 55–9, 88; 6 [1809], 359; Royal Society of London, Philosophical Transactions, 59 [1769], 170–93, 228–40, 273–80, 327–58, 374–8, 407–31; Francisco de [i.e., Franz Xavier von] Zach, Tabulae Motuum Solis Novae et Correctae ex Theoria Gravitatis et Observationibis Racentissimis Erutae … [Gotha, 1792], 29; Brooke Hindle, David Rittenhouse [Princeton, 1964], 253–4; DAB description begins Allen Johnson and Dumas Malone, eds., Dictionary of American Biography, New York, 1928–36, 20 vols. description ends , 6:236–7).

At a meeting presided over by TJ on 2 Mch. 1798 the Philosophical Society agreed to pay Samuel Lewis’s bill of $5.24 for his work filling the diplomas of 31 new members over the previous eight months (bill in PPAmP, in Lewis’s hand, with Samuel H. Smith’s endorsement of the society’s action, TJ’s signature, and Lewis’s receipt of payment on 6 Mch. 1798; APS description begins American Philosophical Society description ends , Proceedings, 22, pt. 3 [1884], 268).

1In his notes on Zach’s letter to Patterson, TJ wrote: “Mr. Schröter astronomer at Lilienthal near Bremen in Hanover has discovered with his 27 feet refractor a spot in 2 of Jupiter’s satellites, by which he observed the rotation of the satellite on it’s axis to be in the same time as his revolution round his planet. this law of motion then may be supposed by analogy general to the secondary planets.”

2TJ’s notes on Zach’s letter: “Ewing.”

3Preceding six words and ampersand interlined.

Index Entries