Critical study of the use of a length unit in the design of 16th to 18th century Italian violins

Until now, the question of geometrical construction (or: reconstruction) of the violin form has been the subject of numerous hypotheses. Without doubt, instruments were designed using the tools of that period, namely, a ruler and a compass and applying the ideas of Pythagoras or Vitruv, to achieve a perfectly balanced instrument. In particular, the question of a “standard unit” is of importance. Previous research mostly dealt in geometrical construction and not in a “standard unit”. Based on our recent discoveries of tools and drawings, we suggest that instruments of the Brescian and Cremonese schools might have used a standard length unit that could have been the Roman oncia. This unit was applied to the Stradivari instruments, later to all Cremonese violins. But initially, the relationship between the proportions did not emerge, until a completely, new construction system, using concentrical circles, was applied. Consequently, all necessary markers for the construction and the radii of the outline can now easily be detected. The construction might be also applicable to violas, violoncellos and even the smaller violins, too. Also the violin scrolls were successfully analyzed.