Arks, which Schultz says were not much used on the Ohio in 1807 were at this period often used by emigrating families to transport themselves down the river.[320] They were long floating rooms, built on a flat bottom, with rough boards, and arranged within for sleeping. Boatmen were hired, provisions were laid in, and when the end of the voyage was reached the boat was sold.[321] They were sometimes called flat bottoms, and described as being "planked up at the sides, and covered at the top." Emigrants generally procured them at Pittsburg and Wheeling, and after reaching their destination sold them to persons wishing to take produce to market.[322] This was a pleasant and cheap method of traveling.[323] About 1817-1818 hundreds of these boats were to be seen on the river, great numbers of them being built at Pittsburg.[324] Tranchepain describes a boat which must have been a form of ark. He says, "During our voyage we passed a great many flat-bottomed boats. Some of them were small, and merely contained an emigrant's family and its furniture. Some of the emigrants who were better off, were going to the Missouri and the Illinois, and their boats, besides their family, contained also a small wagon, and two or three horses. These boats are built in the shape of a parallelogram, whose sides are in the ratio of three, four, or even five to one. They are planked up on each side and behind, and are protected by a slightly curved roof made of thin boards, their height being in the interior about that of a tall man. The upper part of the front, and a few feet on each side of the front are left open like a sort of balcony. From this opening project two long oars which serve to steer the boat, and, in case of necessity, to move it out of the way either of a sand bank, or of a mass of drift wood. Each boat is often divided into two or more apartments, one of which has a fireplace and chimney; so that each of these strange habitations might not inappropriately be termed a floating cottage."[325] Flint describes the flat boats used by emigrants as being from forty to one hundred feet in length, fifteen feet wide, and carrying from twenty to seventy tons. They were very large and roomy, and had separate apartments, fitted up with chairs, beds, tables, and stoves. He says, "It is no uncommon spectacle to see a large family, old and young, servants, cattle, hogs, horses, sheep, fowls, and animals of all kinds, bringing to recoll-ection the cargo of the ancient ark, all embarked and floating down on the same bottom; and on the roof the looms, ploughs, spinning wheels, and domestic implements of the family."[326] Family boats cost from $30 to $50 in Pittsburg.[327] These boats were sometimes tied end to end, two boats carrying as many as forty people.[328] In 1818-1820 "family boats are almost continually in sight," on the Ohio, near Louisville.[329]