Only three wool-carding machines attributed to the hands of the Scholfields are known to exist today. All are 24-inch, single-cylinder carding machines of the same general description (see fig. 8). They differ only in minor respects that probably result from subsequent changes and additions. One (fig. 9), now located in the Plymouth Carding House, at Greenfield Village, Dearborn, Michigan, was discovered in Ware, Massachusetts. Another (fig. 10), now at Old Sturbridge Village, Sturbridge, Massachusetts,[16] was uncovered in a barn in northern New Hampshire. The third (fig. 1), is in the U.S. National Museum in the collection of the Division of Textiles. Both it and the Dearborn machine have in former times been described as "the original Scholfield woolen card." It is a romantic but unsubstantiated idea that either of these is the first Scholfield carding machine set up in the Byfield factory in 1794. The author's opinion is that all three were built by Arthur Scholfield during his years in the Pittsfield factory. Examination of the National Museum machine supports this opinion. The woods used are all native to the New England region. The frame, the large cylinder and the roller called the fancy are constructed of eastern white pine (the Sturbridge machine is also constructed principally of pine). The joints of the main frame are mortised and tenoned. At the doffing end the main frame and cross supports are numbered and matched, I to IIII, and at the feed end they are numbered V to VIII but were mis-matched in the original assembly. Further rigidity is achieved by means of hand-forged lag screws. The arch of the frame is birch and the arch arm maple. The 14-inch doffer roller is made of chestnut.[17] The iron shafts are square and turned down at the bearings. The worker rollers are fitted with sprockets and turned by a hand-forged chain. The comb plate, stamped "Standring," is hand filed, and is undoubtedly one of those made before the "teeth-cutting machine" was smuggled from England, for although one-third of the plate is quite regular, the size and pitch of the teeth in the remaining two-thirds are irregular. Part of this irregularity might be explained as having been caused by the hand-sharpening of a plate originally cut by machine, but the teeth in one 2-inch span not only vary in size but have a pitch that would have been impossible to produce after the original plate had been made.[18]