Glaucus' craft

Explanation

either of things easily wrought, or of things wrought with utmost care and skill. For a certain Hippasus made four bronze discs so that their diameters were equal, but the thickness of the first was four-thirds of the second, three-halves of the third, and double the fourth, and when struck they produced a certain harmony. And Glaucus is said to have been the first to perceive the notes of the discs.