��His fingerboards were also of maple, and were sometimes handsomely inlaid. Some specimens of his fittings, removed from the instruments by Vuillaume and Gand, were presented by them to the Museum of the Paris Conservatoire, where they may still be seen (nos. 6, 10, 114, 115).
In another important detail of the violin, the bridge, Stradivari effected the final im- provement: and it may be said that he has a monument in every violin bridge in the world. Before the Amatis, the bridge had been cut almost at haphazard. The Amatis reduced it to something approaching the present normal form (see the engravings in Fe"tis, Antoine Stra- divari, p. 95), but Stradivari made the final alteration. This consisted in abandoning, for the lower half of the bridge, the principle of the arch, and substituting for it a firm bar rest- ing on a foot near each end. The upper part of the bridge is an arch, formed by the 'heart' or central hole; and by means of the massive bar below, the vibrations excited by the strings in this arched upper part are regulated, and trans- mitted by the feet to the body of the instru- ment. Slight as the improvement seems, it was a great discovery : and since his time the form of the bridge has never been changed. [See BRIDGE.] So important is the bridge to the violin, that had Stradivari effected nothing else, this would have been sufficient to make him famous. Another great service which he rendered to violin-making consisted infixing the exact shape of the soundholes and their relation to the corner blocks. Fortunately we have preserved in the Delia Valle collection (no. 25), in the great maker's own autograph, his rule for placing the soundholes. It is inscribed 'Regola per collo- care le ff delli Violini, Viole, Violoncelli.' The explanation of this is, that it was one of the fixed principles of Stradivari, in which he dif- fered from his predecessors, that the same laws governed the proportions of all members of the violin family, as distinguished from the viol family, which includes the viola da gamba and double-bass, and is governed by other proportions. The diagram is adapted to the mould 'P, f which, as noted above, indicates 'Piccolo' or 'small pattern,' and was made on Feb. 25, 1705.
This diagram af- fords an interesting
problem to students of the mechanism of the violin. Whatever the rule may be, the sound- holes of Stradivari are all traced in accordance with it. The writer has his own solution of the problem, but it would be out of place in the pre- sent article.
The fine tone and the lasting wear of Stradi- vari's instruments undoubtedly depend on the thoroughness with which the mechanical part of the work is executed. A good violin is like a good watch : all its ' works ' must be of per- fect materials, and accurately put together. Nothing could be more perfect than the internal finish of the violins of Stradivari. The wood selected is solid, sound, and sonorous. The pine is of the best quality from Switzerland and the Trentino : the thicknesses and the lines of the pattern are all determined with scientific ac- curacy: the inner framework, consisting of the blocks and linings, is of willow from the banks of the Po about Cremona. It is solidly con- structed, and the bridge and soundholes are so arranged as to produce by its aid a powerful vibration of the belly under the strings. The external finish equally exhibits marks of high mechanical excellence. The purfling is executed with a precision which cannot be appreciated without a magnifying glass. The lines are ad- mirably firm and perfect, and fully display that mastery of curves in which Stradivari was pre- eminent. And here may be noticed a singular freak in which the great maker occasionally in- dulged. Instead of cutting the several outlines of the fiddle and those of the scroll and sound- holes to the usual curves, Stradivari in some in- stances made these outlines polygonal, being composed of a series of short straight lines. The purfling follows the polygonal outline, and is also polygonal. It is hard to see what motive he can have had in producing these singular in- struments, except to show his extraordinary skill as a purfler. Viewed from a certain dis- tance, these instruments exhibit the ordinary appearance. The Marquis Delia Valle has a viola, and Mr. Vonwiller, a violin, of this pe- culiar pattern.
The varnish used by Stradivari in his earlier years is similar to that of Nicholas Amati, in texture and in the method of applying it. In colour there is this difference, that Stradivari avoids the favourite brownish tint of Amati, and generally employs a more or less pronounced yellow. It is oil varnish of a soft and penetrating nature, apparently permeating the wood to some depth beneath the surface, so that when the body of the varnish is worn off the colour and substance appear to remain. After 1684 he began to use a thicker and more lustrous varnish of a reddish tint ; and this colour he ultimately employed to the exclusion of others. The staring effect of the red tint on the back of the fiddle seems to have suggested to Stradivari the device of ' breaking up ' the varnish on the back, thus imitating the effect of wear. When employed by a skilful workman this device lends great addi- tional beauty to the work in the connoisseur's eye : and the example has been generally fol- lowed. 'Breaking-up' is a peculiar and difficult branch of the varnisher's art. Many good makers have failed in it : next to Stradivari, Vuillaume succeeded best. In the instruments of his latest years Stradivari sometimes reverted to the brown