Download or read book Letter to Mons. Dubourg : on the Nature of Sea-coal. From: Memoirs of the Life and Writings of Benjamin Franklin ... written by Benjamin Franklin and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Benjamin Franklin tender the opinion that "sea-coal has a vegetable origin, and that it has been formed near the surface of the earth." He describes a visit to a coal mine at Whitehaven near Cumberland, England, into which he descended until he was some 800 fathoms beneath the surface of the ocean.