In 1794, Wilkinson designed a screw-cutting lathe with a slide rest on which he obtained a patent in 1798. In 1806 he developed a smaller version in which two bearing points were in line on the front prismatic way while the third rested on a flat rib at the back of the bed. Once the front way had been made as straight as pos-sible the flat way could be contoured with a file to correct for irregularities that remained in the prismatic way. It is not known how many of these lathes Wilkinson produced in his own plant, but in 1848 a Senate Committee found that there were more than 200 such lathes in use in government workshops alone. Henry Maudslay, the Englishman who is generally credited as a lathe pioneer, produced a lathe in 1800 that had many of the features of the 1798 Wilkinson patent. Lathes produced in America universally used these features until about 1840, and some were produced until about 1901. Wilkinson produced other types of machinery, using a centerless technique to grind spindles for textile machinery. Robert S. Woodbury, in his "Studies in the History of Machine Tools" said that "we may credit David Wilkinson with being the founder of the American machine-tool industry."