Thomas Jefferson Papers

To Thomas Jefferson from John Churchman, 2 April 1792

From John Churchman

No. 183 South 2nd Street
April 2nd. 1792.

My Honourable Friend

Notwithstanding the report of the committee on my late memorial to Congress, it does not appear very likely that any money will be granted the present session for the proposed voyage; yet as this is a pleasing pursuit, I am led to consider the next step in order if possible to bring the Magnetic principles to the test, as these may be proved by having a sufficient number of observations at places whose situations are well determined, I have already had some correspondence with some members of foreign learned Societies on this subject.

I should be very sorry to propose anything that might prove a disappointment to another, but hearing accidentally that one of the Clerks had this day left the office of the Secretary of State, I am tempted to offer myself as a candidate for that vacant place, in hopes such a situation might promote my own improvement, and be favourable for such a foreign correspondence: yet I am afraid it may be thought improper to place confidence in a person who is as much of a stranger as myself. This consideration together with a diffidence of my own abilities prevented me from mentioning this matter when I had the first interview.

I hold myself under many obligations for the candour manifested in explaining to me the difficulty of making observations of the variation at Sea, I believe this is the principle objection against the Magnetic Scheme being generally useful. But a certain Kennet McKulloch (Instrument maker to the duke of Clarence) has published a number of Letters in the Appendix to the account of his new Invented Azimuth Compass. They are from some of the Officers of the British navy, and some others. They declare that by his new invented Instrument the variation can easily be found on the roughest Sea; and in Nicholsons Philosophy it is said from experience that the Magnetic variation may be easily observed in moderate weather, to the certainty of a less error than ten minutes, so that in time I hope the principle difficulties will vanish.—With the greatest Sentiments of respect, I hope to be permitted to make an offering of my Service & esteem,

John Churchman

P.S. An answer will be very agreeable tomorrow.

RC (DLC: Washington Papers); endorsed by TJ and recorded in SJL as received 3 Apr. 1792; at head of text in clerk’s hand: “John Churchman asks for a clerkship in the state office.”


Churchman’s memorial to congress was the latest in a series of attempts to garner government support for his experiments using magnetic fields to produce more accurate maps, charts, and globes. Petitioning first in April 1789, Churchman requested Congress to increase the patent law penalties for unlawful copying of maps and globes, and to finance an expedition to Baffin Bay, Canada. Although two different committees recommended his proposals, the House withheld approval (JHR description begins Journal of the House of Representatives of the United States, Washington, Gales & Seaton, 1826- description ends , i, 14, 18, 137, 366, 483, 521, 530). letters in the Appendix:Kenneth MacCulloch, An Account of the New, Improved Sea Compasses, made by … K. McCulloch, with reports of their practical utility … by P. d’Auvergne (London, 1789). Nicholsons philosophy: William Nicholson, An Introduction to Natural Philosophy, 3d. ed. (Philadelphia, 1788). See Sowerby, description begins E. Millicent Sowerby, comp., Catalogue of the Library of Thomas Jefferson, 1952-1959, 5 vols. description ends No. 3725.

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