Enclosed I send you a Letter and sundry Papers I lately received from Mr. Eckhardt of Utrecht, a most ingenious Mechanician whom I first knew in London. You will see what he desires, and what Answer I have made him. If you can do him any Service, I need not pray you to do it because you have a Pleasure in assisting Genius: Show if you please what he says of the Balloons, to Mr. Montgolfier. I long to see you, being ever Yours most affectionately