From James Colder
Washington June 12 1804
I resolvd sometime Ago should I ever come near the President to tell him of a small Mistake made in his Book Notes on Virginia he says in his description of Rockbridg that One Axis is many times longer than the transvers or words to that purpose & that the Bridge has an Elliptical form1 Now in an Elipse there are only two Axes the transverse & the Conjugate it may have many Conjugate Diameters but has no More than Conjugate Axis.2 A Single word would set it right & I pray Enquire of others & have it righted for my Own part I am a private Man in Life & would not Change it on Any Account I do not seek to flatter the President & would not Offend him with Design—As to Politicks I am as Ignorant as Any Man whatever & this I remember I was relev’d some years ago of a tax of 35 Dollars for Land. I am respectfully Sir Your Obedt Sert
Jas Colder of Baltimore County
1. In describing the Natural Bridge in Rockbridge County, Virginia, Jefferson wrote: “The arch approaches the Semi-elliptical form; but the larger axis of the ellipsis, which would be the cord of the arch, is many times longer than the transverse.” Jefferson later replaced “transverse” with “semi-axis which gives it’s height” (Thomas Jefferson, Notes on the State of Virginia, ed. William Peden [1954; reprint, Chapel Hill, N.C., 1995], 24, 263).
2. At this point in the RC, Colder drew an ellipse with axes labeled “transverse” and “Conjugate.”