Philad 25 Nov 1808
I recd your letter and the spectacles. I was fearfull I should not be able to put Dble glasses in such small frames and did think of writting you and directing how to secure the glasses in the circular spects from moving round. however I have put in two pairs and hope they will please, the glasses that were in that suites your present vision I found to be 16 inch focus the pair of Dble eyes in are 16—& 20 inch focus the other pair are 12 & 16—you direct to have but one number difference between the two magnifyers but in a long focus it requires a greater distance then when shorter the difference between 16 & 20 is not greater then between 8 & 9—when I put in circular Dble glasses to prevent them moving round I make a little thin glue & whiting the consistance of thick cream and work it in by the edge of the glass in a few minutes it gets hard & secures the glass—if those now sent are found too small and the others cannot be made to answer by sending them on I can put them into an oval form and fit eyes in them. The price of those two pair is two Dollars
I am sir yours respectfully
DLC: Papers of Thomas Jefferson.