To Robert Patterson
Monticello Sep. 11. 11.
The inclosed work came to me without a scrip of a pen other than what you see in the title page. ‘A Monsr le president de la societé.’ from this I conclude it intended for the Philosophical society, & for them I now inclose it to you. you will find the notes really of value. they embody and ascertain to us all the scraps of new discoveries which we have learnt in detached articles, from less authentic publications. M. Gudin has generally expressed his measures according to the old, as well as the new standard, which is a convenience to me, as I do not make a point of retaining the last in my memory. I confess indeed, I do not like the new system of French measures, because not the best, and adapted to a standard accessible to themselves exclusively, and to be obtained by other nations only from them. for, on examining the map of the earth, you will find no meridian on it, but the one passing thro’ their country, offering the extent of land on both sides of the 45th degree, and terminating at both ends in a portion of the ocean, which the conditions of the problem for an universal standard of measures require. were all nations to agree therefore to adopt this standard, they must go to Paris to ask it; and they might as well, long ago, have all agreed to adopt the French foot, the standard of which they could equally have obtained from Paris. whereas the Pendulum is equally fixed by the laws of nature, is in possession of every nation, may be verified every where, & by every person, and at an expence within every one’s means. I am not therefore without a hope that the other nations of the world will still concur, some day, in making the pendulum the basis of a common system of measures, weights & coins, which applied to the present metrical systems of France and of other countries will render them all intelligible to one another. England and this country may give it a beginning, notwithstanding the war they are entering into. the republic of letters is unaffected by the wars of geographical divisions of the earth. France, by her power & science, now bears down every thing. but that power has it’s measure in time by the life of one man. the day cannot be distant, in the history of human revolutions, when the indignation of mankind will burst forth, and an insurrection of the universe against the political tyranny of France will overwhelm all her arrogations. whatever is most opposite to them will be most popular, and what is reasonable therefore in itself cannot fail to be adopted the sooner from that motive. but why leave this adoption to the tardy will of governments, who are always, in their stock of information, a century or two behind the intelligent part of mankind? and who have interests against touching antient institutions? why should not the College of the literary societies of the world adopt the second pendulum as the unit of measure, on the authorities of reason, convenience, & common consent? and why should not our society open the proposition by a circular letter to the other learned institutions of the earth? if men of science, in their publications, would express measures always in multiples & decimals of the pendulum, annexing their value in municipal measures, as botanists add the popular to the botanical names of plants, they would soon become familiar to all men of instruction, and prepare the way for legal adoptions. at any rate it would render the writers of every nation intelligible to the readers of every other, when expressing the measures of things. the French, I believe have given up their Decadary Calendar, 1 but it does not appear that they retire from the centesimal division of the quadrant. on the contrary M. Borda has calculated, according to that division, new trigonometrical tables, not yet I believe printed. in the excellent tables of Callet, lately published by Didot in stereotype, he has given a table of Logarithmic Sines & Tangents for the hundred degrees of the quadrant, abridged from Borda’s manuscript. but he has given others for the sexagesimal division, which being for every 10″ thro’ the whole table, are more convenient than Hutton’s, Scherwin’s or any of their predecessors. it cannot be denied that the Centesimal division would facilitate our arithmetic, and that it might have been preferable, had it been originally adopted; as a numeration by eights would have been more convenient than by tens. but the advantages would not now compensate the embarrasments of a change.
I extremely regret the not being provided with a time piece equal to the observation of the approaching eclipse of the sun. can you tell me what would be the cost in Philadelphia of a clock, the time-keeping part of which should be perfect? and what the difference of cost between a wooden & gridiron pendulum? to be of course without a striking apparatus, as it would be wanted for astronomical purposes only. Accept assurances of affectionate esteem & respect.
PoC (DLC); at foot of first page: “Doctr Patterson.” Enclosure: Paul Philippe Gudin de la Brenellerie, L’Astronomie, Poëme en Quatre Chants (Paris, 1810; Sowerby, description begins E. Millicent Sowerby, comp., Catalogue of the Library of Thomas Jefferson, 1952–59, 5 vols. description ends no. 4495).
TJ proposed the oscillation of a rod pendulum as the basis of a common system of measures, weights & coins in his Report on Weights and Measures, 4 July 1790 (PTJ description begins Julian P. Boyd, Charles T. Cullen, John Catanzariti, Barbara B. Oberg, and others, eds., The Papers of Thomas Jefferson, 1950– , 31 vols. description ends , 16:602–75). He believed that France’s hegemony and the life of one man, Napoleon, would end at the same time. In 1806 that ruler abolished the decadary calendar in use in France since early in the 1790s, which had assigned three ten-day weeks called décades to every month, and returned the nation to the traditional Gregorian calendar (Connelly, Napoleonic France description begins Owen Connelly and others, eds., Historical Dictionary of Napoleonic France, 1985 description ends , 93–4). TJ alluded to Charles hutton’s Mathematical Tables: containing Common, Hyperbolic, and Logistic Logarithms (London, 1785; Sowerby, description begins E. Millicent Sowerby, comp., Catalogue of the Library of Thomas Jefferson, 1952–59, 5 vols. description ends no. 3697), and Henry scherwin’s (Sherwin’s) Mathematical Tables, contrived after a most comprehensive method (London, 1705, and later editions).
1. Reworked from “decimal Calendar, of months.”
- American Philosophical Society; TJ forwards material to search
- Borda, Jean Charles; and trigonometrical tables search
- Callet, Jean François; Tables of Logarithms search
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- coinage; universal standard for search
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