Washington Nov. 19. 06.
It has not been in my power sooner to answer your favor of the 14th. I measured the distance between center & center of the glasses of a pair of spectacles I had of you & now use & found it 2⅜ I. I then endeavored to ascertain the distance of the two axis of the eyes by looking into a mirror & applying a pair of dividers, & found it 2½ I. but I ought to have adverted to what you mention the convergence of the two Axis when directed to a book. you will therefore be so good as to make the distance such as your experience has found to be necessary, observing with exactness the other dimensions. it is not in my power to send you a glass from those I use, because they are in constant use, & I have asked compleat sets of glasses to both pair, as they may hereafter be an accomodation to a younger person. I thank you for your ready attention to this little commission & present you my salutations & best wishes.
DLC: Papers of Thomas Jefferson.