1Thomas Jefferson’s Observations at Monticello Related to Calculation of Latitude, 11 October 1815–31 January 1816 (Jefferson Papers)
date Merid. Alt. by circle same halved merid. Alt. from horizon difference ⊕ error of instrum. ...
2To James Madison from Eleazer W. Ripley, 11 October 1815 (Madison Papers)
In a recent communication to the Adjt. & Inspector General, I solicited the favor of an order to...