Thomas Jefferson Papers

Thomas Jefferson to James Deneale, 8 July 1820

To James Deneale

Monticello. July 8. 20.


Your favor of the 2d has been recieved with the mapping instrument for platting lands by latitude and departure. it bears no analogy at all to the method of platting explained by me to mr Girardin some years ago. that was in the usual mode of course and distance, and was merely a substitution of East & West lines instead of Meridians, transferring those lines from station to station by the triangled parallel ruler; & applying the protractor to the edge of the ruler, at the new station instead of drawing the line actually on the paper. this method is quicker, neater, and less liable to errors than the common, but is a mere manual abridgment of trouble, not at all claiming the honors of invention.   Having never been in the practi[ce of] platting in the way to which your instrument is applicable, [I am] not a judge of the degree of convenience to be derived from it’s use. I return it with assurances of my respect.

Th: Jefferson

PoC (DLC); on verso of reused address cover to TJ; torn at seal, with two words rewritten by TJ; at foot of text: “Mr James Deneale”; endorsed by TJ.

TJ described his method of platting in an 18 Mar. 1814 letter to Louis H. Girardin.

Index Entries

  • Deneale, James; letter to search
  • Deneale, James; surveying instrument and method of search
  • Girardin, Louis Hue; TJ sends surveying instructions to search
  • protractor search
  • surveying; and protractor search
  • surveying; J. Deneale’s instrument and method of search
  • surveying; TJ provides instructions to L. H. Girardin on search