VI. THE ARCHING.
It does not seem to me probable that Stradivarius acted without mature deliberation in making the arch of the back and belly, taken together, of the same height as the ribs, viz.: 30 m/m.; of course, I am speaking now of the violins made during his prime. If the back and belly are placed one upon the other, the height will amount to 30 m/m., the entire external diameter, therefore, must be 60 m/m., since the ribs, as already stated, have a height of 30 m/m. I am certainly of the opinion, that Stradivarius substantiated these proportions by experiments. There are, however, exceptions; the greatest of the deviations from this rule which has come under my notice, consisted in the middle line measuring 70 m/m., reckoning from the upper edge of the belly to the lower edge of the back. No doubt, this violin, made in 1710, was an experiment, the average measurement being considered to be from 58 to 62 m/m. Now and again, Stradivarius made the arch lower, whether intentionally or from want of wood, I am not in a position to say. In this case he makes the ribs correspondingly higher, so that the above-mentioned measurement may still be 60 m/m. Stradivarius has also occasionally made the arch of the back less than 15 m/m., and by way of compensation, in this case, has increased the arch of the belly. I am of opinion, however, that these deviations are to be ascribed more to experiment than to accident. He never trusted to chance in his work, but in the most careful way reflected upon it and took into consideration all circumstances in connection with it. The arch given as an example in Fig. 6, is taken from a Stradivarius violin of the year 1713, and as the belly and back are both of equal height, viz.: 15 m/m., the entire height amounts to 60 m/m.