Depicted in Figure 20 is the frequency of the side depth at the bottom of the guitar. The side depth at the bottom of the instrument ranges considerably from a minimum of 68 mm to a maximum of 110 mm.
Figure 20: Side Depth Frequency at Bottom of Guitar
In Figure 21, lower bout width is used as a proxy for body size to determine any correlation between side depth and body size. There is not a strong correlation between side depth at the bottom of the instrument and lower bout width with R2 only 0.13. The six small guitars from the second epoch are grouped at the lower left. Also shown is SEU 4, the second epoch instrument with a 661 mm scale length. Romanillos indicates that SEU 5 is not wholly Torres work. FE 8 with side depth of 110 mm is noteworthy as this is the guitar that won first place in the Seville Exhibition of 1858.
Figure 21: Side Depth at Bottom of Guitar vs. Lower Bout Width
Figure 21 would seem to indicate that Torres choice of side depth was not dictated by body size for most of his instruments. Figure 22 may provide more insight, especially when compared with Figure 8. Even though side depth at the bottom of the guitar is not well correlated with lower bout width, Figures 22 and 8 seem to show a similar trend: as Torres evolved to a more consistent use of a wider lower bout in his second epoch, side depth also trended downwards.
Figure 22: Side Depth at Bottom of Guitar by Construction Sequence
Figure 23 depicts the taper of the side from top to bottom by construction sequence. Note that positive taper indicates greater depth at the bottom vs. the top. It appears that Torres targeted taper in the range of 0 mm to 10 mm for most of his guitars. There may also be evidence of a trend over time towards less taper which would be consistent with the trend towards shallower side depth.
Figure 23: Side Taper Top to Bottom by Construction Sequence
