A double-headed mace

Thomas Mace, stout defender of women lutenists, earned his place in the pantheon of great eccentrics with his invention of the magnificent Lute Dyphone. The Dyphone cunningly combined two instruments in one, the Majestick Theorboe (on the right) and the High Improved French Lute, with no less than fifty strings between them. Mace says that he himself built the only Dyphone in existence in 1672. I'm not aware that anyone has tried to build one since, despite the numerous advantages detailed by the inventor.

Mace's reason for creating the Dyphone was an unexpected one: his deafness. He could no longer hear the soft sound of a normal lute, and was searching for something stronger. The Dyphone proved to be 'absolutely the Lustiest or Loudest Lute, that I ever yet heard'. Even so, he still needed to hold his teeth to the edge of the instrument to hear everything distinctly.

Mace was already in his 60's when he published Musick's Monument, in which the Dyphone appears, in 1676. The book was published thanks to the generosity of 300 subscribers, each of whom took a copy ('in sheets' - the binding was extra) for twelve shillings. Which was quite a lot of money: equivalent to £81 today using the retail price index, or a staggering £903 using average earnings. One of the subscribers was Isaac Newton, like Mace a member of Trinity College, Cambridge.