Another important British patent was granted in 1748 to Daniel Bourn, who invented a machine with four carding rollers set close together, the first of the roller-card type (see fig. 5). To produce a practical carding machine, however, several additional mechanical improvements were necessary. The first of these did not appear until more than two decades later, in 1772, when John Lees of Manchester is reported to have invented a machine featuring "a perpetual revolving cloth, called a feeder," that fed the fibers into the machine.[2] Shortly afterward, the stripper rollers[3] and the doffer comb[4] (a mechanical utilization of Paul's hand device) were added. Both James Hargreaves and Richard Arkwright claimed to be the inventor of these improvements, but it was Arkwright who, in 1775, first patented these ideas. His comb and crank (see fig. 6) provided a mechanical means by which the carded fibers could be removed from the cylinder. With this, the cylinder card became a practical machine. Arkwright continued the modification of the doffing end by drawing the carded fibers through a funnel and then passing them through two rollers. This produced a continuous sliver, a narrow ribbon of fibers ready to be spun into yarn. However, it was soon realized that the bulk characteristic desired in woolen yarns (but not desired in the compact types such as worsted yarns or cotton yarns) required that the wool be carded in a machine that would help produce this. [Illustration: Figure 7.--NEWBURYPORT, MASSACHUSETTS, in 1796, AN ENGRAVING FROM JOHN J. CURRIER'S _History of Newburyport, Massachusetts_, 1764-1909, vol. 2, Newburyport, 1906-09.] In carding wool it was found more effective to omit the flat stationary cards and to use only rollers to work the fibers. The method of preparing the sliver also had to be changed. Since it was necessary to remove the wool fibers crosswise in the sliver, a fluted wooden cylinder called a roller-bowl was used in conjunction with an under board or shell. As a given section of the carded wool was fed between the fluted cylinder and the board, the action of the cylinder rolled the fibers into a sliver about the diameter of the finger and the length of the cylinder. Although these were only 24-inch lengths as compared to the continuous sliver produced by the Arkwright cotton-carding machine,[5] wool could still be carded with much more speed and thoroughness than with the small hand cards. This then was the state of mechanical wool carding in England in the 1790's as two experienced wool manufacturers, John and Arthur Scholfield, planned their trip to America. John and Arthur Scholfield