The largest bass available for testing was a huge Abraham Prescott, with a 48-in. (122-cm) body length, made in Concord, N.H., in the early 1800's but even that was not big enough! A tiny pochette, or pocket fiddle, from the Wurlitzer collection, with a body length of 7 in. (18 cm) had the right cavity resonance, but its body resonance was much too low.
The body length of each of the new instruments has been one of the controlling factors in all of our experiments. Thus it was decided that the best way to arrive at the dimensions for the largest and smallest would be to plot a curve of body lengths of known instruments, to check against their resonance placement and string tuning. This working chart is shown in figure 3 in which linear body length is plotted against the logarithm of wavelength. The curve for the new instruments was extended in a smooth arc to include the contrabass frequency at the low end and the treble frequency at the upper end, an octave above the normal violin. This procedure gave a projected body length of 51 in. (130 cm) for the contrabass and 10.5 in. (26.5 cm) for the treble. Of course rib height and enclosed air volume were separately determined by other considerations.