As already pointed out, he had been working for many years on the problem of screw cutting. Maudslay had carried this to a more refined point than any other mechanic. Profiting by Maudslay’s experience, Clement began the regular manufacture of taps and dies in 1828, using the thread standards developed by Maudslay as his basis. He introduced the tap with a small squared shank which would fall through the threaded hole and save the time of backing out. He is said to have been one of the first in England to employ revolving cutters, using them to flute his taps. While he may have used such cutters, he was certainly not the first to do so, as they were in use in France at least thirty years earlier. He did important work in developing the screw-cutting lathe, again improving upon Maudslay’s work and increasing the accuracy of the device. He was given a number of gold medals for various improvements in it, as well as for his work on the planer. We have already referred to his “great planer” and will only say here that of those who contributed to the early development of this machine none have had a greater influence. He executed the work on Charles Babbage’s famous calculating machine, which attracted so much attention eighty years ago and was probably the most refined and intricate piece of mechanism constructed up to that time. Clement was a rough and heavy-browed man, without polish, who retained until the last his strong Westmoreland dialect. At no time did he employ over thirty workmen in his factory, but they were all of the very highest class. Among them was Sir Joseph Whitworth, who continued his work on screw threads and brought about the general use of what is now known as the Whitworth thread. Richard Roberts, the last of those mentioned as inventors of the metal planer, was born in Wales in 1789. Like most of the early mechanics he had little or no education, and as soon as he was strong enough he began work as a laborer in a quarry near his home. His mechanical aptitude led him into odd jobs and he soon became known for his dexterity. He finally determined to become a mechanic and worked in several shops in the neighborhood. He was employed for a time as pattern maker at John Wilkinson’s works at Bradley, and is one of the few links between Wilkinson, who made the first modern metal-cutting tool--his boring machine--and the later generation of tool builders.