11To Thomas Jefferson from Thomas Paine, [May? 1788] (Jefferson Papers)
I enclose you a Problem not about Bridgs but Trees, and to explain my meaning I begin with a fountain. The Idea seems far fetched, but fountains and Trees are in my walk to Challiot. Suppose Fig. 1st a fountain. It is evident 1st. That no more water can pass thro the branching Tubes than pass thro the trunk. 2d. That admitting all the water to pass with equal freedom, the sum of the squares of...