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Towards establishing the original state of the three-manual harpsichord by Stefano Bolcioni, Florence, 1627, in the Russell Collection of Early Keyboard Instruments, Edinburgh
an article published in The Galpin Society Journal, 53 (2000) 168-200 by Grant O'Brien |
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Analysis of the unit of
measurement used in the construction of the Edinburgh Bolcioni harpsichord,
originally a single-manual instrument:
The
value of the Florentine soldo used in
the Edinburgh Bolcioni can be calculated in the usual way which has been
demonstrated in my article in the previous volume of this Journal. The tangent of the tail angle is tan 38½º =
0.795
@
0.80 = 
=
. The numbers
when applied to
the component measurements of the tail give a soldo greater than any known historically in Italy. But the ratio
suggests that
the two orthogonal components of the triangle that form the tail angle are 8 soldi and 10 soldi which, mathematically, would form an angle of 38.66º. Not surprisingly this angle is very close to
the measured angle of 38½º, and well within the error of measurement. The length of the two orthogonal sides
constituting the components of the tail side (see Table 1)
gives an approximate estimate of the size of the soldo which can then be applied to the other measurements of the
baseboard, the original wrestplank, the original string scalings, and all of the
other original parts and design features of the instrument in a way similar to
that already described for the other instruments discussed in my paper in the
previous volume of this Journal. A
summary of the original measurements of the baseboard, baseboard construction
lines and the case height in soldi is
given in Table 2, where the lengths of the soldo calculated from each of these are
shown at the right:
Measurement Local Length of
in mm unit soldo
Tail angle component parallel to spine: 273½ = 10 soldi → 27.35
Tail angle component perpendicular to spine: 220 = 8 soldi → 27.50
Spine (long bass side)*: 1981½ = 72½ soldi → 27.33
Baseboard
width: 756½ = 27
soldi
→ 27.34
Cheek (short treble
side)*: 537½ = 19soldi
→ 27.33
Case sides height: 219 = 8 soldi → 27.38
Case front to nut line (bass side)*: 164½ = 6 soldi → 27.42
Case front to nut line (treble side)*: 273½ = 10 soldi → 27.35
Case front to belly rail (bass
side)*: 391½ = 14
soldi → 27.31
Case front to belly rail (treble
side)*:
373½ =
13soldi → 27.33
Total: 5191 = 189
soldi Average: 27.345mm
*These
measurements have each been corrected by adding 20½mm.
Table 2 - Original case measurements and the calculation of the Florentine soldo
Three-manual harpsichord by Stefano Bolcioni, Florence, 1627
Russell Collection of Early Keyboard Instruments, Cat. No. HT1-SB1627.4
This calculation gives a value of the soldo that compares with a value of 27.29mm found for the 1631 Bolcioni harpsichord in Yale University, a value of 27.34mm found for the 1641 Bolcioni virginal in the Musikinstrumentenmuseum in the University of Leipzig (for both of these see the analyses in my paper in the previous volume of this Journal), a value of 27.341mm given by both Diderot (1751) and Krünitz (1788)[1], a value of 27.408mm given by Larousse[2] and the value of 27.53mm given by Colonel Cotty (1819)[3]. The similarity to one another of the values of the soldo found for the various Bolcioni instruments, and the similarity of these to the values given in the historical sources of metrology, confirms that they were all made in Florence using the Florentine braccio and soldo, and this fact also helps to confirm that the instruments were indeed all made by Bolcioni[4].
The measurements from Table 2 are shown in Figure 1 where the actual dimensions in millimetres with the measured tail angle are shown on the left. The same measurements in units of the Florentine soldo, and the nominal tail angle resulting from these are shown on the right.
Figure 1 - Baseboard measurements in millimetres
(left) and
in units of the
Florentine soldo used by Bolcioni =
27.345mm (right)
Three-manual harpsichord by Stefano Bolcioni, Florence, 1627
Russell Collection of Early Keyboard Instruments, Cat. No. HT1-SB1627.4
The shaded portion at the front of the baseboard seen in Figure 1 shows the amount which seems to have been removed in order to accommodate the non-original C/E to c3 keyboard with pedal pull-downs. This shortening of the baseboard occurred in one of the numerous intermediate states of the instrument. The strongly-angled line indicates the original position of the nut, and the double lines behind this indicate the original position of the sides of the lower belly rail. Clearly, if my assumption about the scroll of this harpsichord having originally been the same as that on the University of Yale Bolcioni so that 20½mm were removed from the baseboard of this instrument, the nut and the belly rail were also positioned using simple integers and fractions of Florentine soldi as would be expected.
The position
of the front of the belly rail involves thirds of a soldo, rather than the more common halves and quarters. This is, however, not as unusual as it seems
at first. As explained in footnote in the
Introduction the soldo was divided into 3 quattrini
(so-called because one quattrino = 4 denari). The quattrino, equal to
of a soldo, was a unit of measurement that
was in common use in Florence, and often quoted when describing the sizes of
objects in Florentine documents and inventories. It is therefore not at all surprising to see measurements among
those found in the layout of the baseboard of this harpsichord involving quattrini or thirds of a soldo.
The fact that all of the measurements after correction are simple
rational numbers in units of the soldo
or its common division indicates that the assumed reduction in the length of
the baseboard of 20½mm is indeed correct.
It would be an unusual coincidence for the numbers to work out this
tidily if the assumed correction were incorrect.
Figure 2 shows a schematic representation of the cheek section, and of the probable original form of the keywell for the Edinburgh Bolcioni. Here the keywell scroll of the Yale University Bolcioni harpsichord of 1631 has been added on at the point where the present join in the cheek begins (dashed line) and the batten in front of the baseboard of the Yale University Bolcioni has been drawn in (shaded). An added section 20½mm wide (shaded) has had to be added to the length of the baseboard in order to accommodate the Yale cheek piece as discussed above.
Figure 2 - Schematic representation of the cheek section[5] and the probable original form of the keywell section
Three-manual harpsichord by Stefano Bolcioni, Florence, 1627
Russell Collection of Early Keyboard Instruments, Cat. No. HT1-SB1627.4
[1] Denis Diderot and Jean Henri le Rond d’Alembert, ‘Pied’, Encyclopédie ou dictionnaire raisonnée des arts, sciences et métiers (Paris, 1751-65) 562-563 and Johann Georg Krünitz, Öconomische Encyklopädie oder allgemeines System der Staats-, Stadt-, und Landwirtschaft, in alphabetischer Ordnung, 15 (Joseph Georg Traßler, Brünn, 1788) p. 519-22 both give lengths as 1440-th parts of the Paris pouce. The length of the Florentine braccio and soldo were calculated by me using the value of the length of the French pouce given by Colonel Cotty, Aide-Mémoire (p. 896 - see footnote 5). My thanks to John Koster for pointing out the Krünitz source to me. Krünitz clearly bases his values on those given by Diderot. He uses the same system of 1440-th parts of the French pouce, and gives exactly the same values as Diderot which were published almost 40 years earlier.
[2] See: Pierre Larousse, Grand Dictionnaire, (Paris, 1874) who gives a braccio with 20 soldi of length 548.17mm.
[3] Colonel Cotty, Aide-Mémoire a l’usage des officiers d’artillerie de France, 2 (Paris, 1819) 896-7 gives a length of 550.6371mm for the braccio da terra divided into 20 soldi.
[4] Unpublished work by me on the instruments of the Florentine makers Francesco Poggio and Bartolomeo Cristofori shows, not surprisingly, that the same Florentine soldo was used in the construction of the instruments of these makers as well.
[5] The moulding shown here on the outside of the case just below the top cap moulding is on the inside of the case everywhere else except for the cheek.