On the Structure and Aims of Two Stringed Devices in Ptol. harm. II, 2

In chapt. II, 2 of the Harmonics Ptolemy describes two peculiar devices, the first referred to as ἑλικὼν, the second unnamed, which on the one hand are not intended for musical performance, but on the other hand seem unnecessary even from the standpoints of acoustics or music theory. This paper aims at investigating the way in which they worked and suggesting what their function might have been.