the model in the course of the present week, with any observations you will be so good as to favor me with." Writing from Washington, July 15, 1808, to Mr. Sylvestre, in acknowledgment of a plow received from the Agricultural Society of the Seine (France), he adds: "I shall with great pleasure attend to the construction and transmission to the society of a plough with my mould-board. This is the only part of that useful instrument to which I have paid any particular attention. But knowing how much the perfection of the plough must depend, 1st, on the line of traction; 2d, on the direction of the share; 3d, on the angle of the wing; 4th, on the form of the mould-board; and persuaded that I shall find the three first advantages eminently exemplified in that which the society sends me, I am anxious to see combined with these a mould-board of my form, in the hope it will still advance the perfection of that machine. But for this I must ask time till I am relieved from the cares which have more right to all my time--that is to say, till next spring;" _i. e._ until after the expiration of his second term as President of the United States. The importance of any step in civilization can be understood only in its relations, antecedent causes and actual results. The _Scientific American_, which is certainly good authority in such matters, ranks Jethro Wood with Benjamin Franklin, Eli Whitney, Robert Fulton, Charles Goodyear, Samuel B. Morse, Elias Howe, and Cyrus H. McCormick, and these are certainly the great names and this a just classification. Each in his way laid the foundation on which all inventors in his respective line have built, and must continue to build, and none of them all came so near perfecting his grand idea as Mr. Wood. His now venerable daughter stated the exact truth when she remarked in a letter not designed for publication: "My father patented the shape and construction of the plow. He took the iron and shaped the plow that turns the furrow for every product of the soil in America. His plow has never been improved. It came from his hand simple and perfect, as it now is, and there is no other plow now in use." It was not the use of cast iron that he invented, although the use of "pot metal" by him occasioned a great deal of hostility to the original Wood plow.