Fulton secured the Danish brig _Dorothea_—a prize of war—and anchored her within safe range from the shore, in easy sight of the crowd of distinguished visitors whom he invited to witness the experiment. The rumor spread that “Mr. Francis,” who had invented and built the machines used by Sir Home Popham against the enemy’s ships at Boulogne, was to try to blow up a three hundred ton brig with one of his novel catamarans. A multitude assembled on the beach eager to see the explosion. Fulton wrote a letter to Lord Castlereigh, the next day, which gives a fine account of all that happened. He says: “Yesterday about four o’clock, I made the intended experiment on the brig, with a carcass of one hundred and seventy pounds of powder; and I have the pleasure to inform you that it succeeded beyond my most sanguine expectations. Exactly in fifteen minutes from the time of drawing the peg and throwing the carcass into the water, the explosion took place. It lifted the brig almost bodily and broke her completely in two. The ends sunk immediately and in one minute nothing was to be seen of her but floating fragments; her main mast was broken in three places; her beams and knees were thrown from her decks and sides, and her deck planks were rent to fibers. In fact, her annihilation was complete, and the effect was most extraordinary. The power, as I had calculated, passed in a right line through her body, that being the line of least resistance, and carried all before it. At the time of her going up, she did not appear to make more resistance than a bag of feathers, and went to pieces like a scattered egg-shell.” The unbelieving statesmen were convinced by this demonstration before their very eyes. Fulton was of course happy and satisfied; and wrote to Benjamin West (whom he affectionately addresses as “Mammy”), giving a graphic account of the event. DOVER, Oct. 16th, 1805. MY DEAR MAMMY WEST;