To Andrew Gwin
Philadelphia Mar. 24. 98.
I wrote to mr Madison, President of the college of Williamsburg, describing to him the experiment I wished him to try with the dipping needle of that college. I did not give him the least hint of the object, but only desired him to hold the meridian of the instrument in the meridian of the place, but with the North end pointing South, and to mark the dip. I inclose you his answer, by which you will percieve that it was not the latitude of the place, which is about 37°½ but 66°¼ being exactly it’s dip when held in the true position of the needle. when you shall have satisfied yourself with the contents of the letter, I will thank you to return it.
I am Sir Your most obedt. servt.