After turning and milling this piece on a lathe and mill using electricity, I became curious how mediaeval balistaria accomplished the same task with only manual tools. The remarkable thing is that brass is quite soft and easily turned, but Payne-Gallwey describes mediaeval bowmakers turning sockets and nuts from blanks of steel. It is difficult to imagine turning steel by hand, even with a so called “pole lathe.” The answer “turns” out to be simply mechanical advantage. Old lathes apparently used a massive wheel rotated manually at first and by water by the end of the seventeenth century. Here are some links on the subject:

• Stuart King describes the history of the lathe and offers some pictures of great wheel lathes;
• Ye Art And Mysterie of Turning details the early development of the lathe;
• Thomas Rettie maintains a site devoted to medaeval woodworking including early lathes; and, of course,
• Wikipedia.