Furthermore when the sternpost is extended to 11 ft 6 inches, the vertical height listed in the *devis*, its rake measured relative to its after face—*BQ*—is also 3 ft. Since the forward and after faces of the sternpost and outer sternpost are not parallel to each other or the rabbet, I suspect that all of the points associated with these measurements were used by the shipwright to lay out these timbers. In terms of design, identifying point *J* at the height of the wing transom is the most important, and the 1½ ft rake measurement to the back of the outer sternpost and the keel timber is consistent with the above analysis for the rake of the stem.

The Midship Frame

Having defined the longitudinal profile of the hull, the transverse limits were established with the midship frame. Deciphering the design of the midship frame was complicated not only by discrepancies with measurements in the *devis* but also with apparent inconsistencies within the archaeological evidence itself.

As in the case of the stem, the archaeologically documented curvature of the midship frame was analyzed geometrically to determine what if any component arcs were used in its design. This work indicated that the lower part of the midship frame was defined on each side by two arcs with centers at points *D* and *K* (*K'*) (Figures 27d, 28a). Extending the arc centered at point *D* upwards a little beyond the level of preservation results in a maximum beam at the midship frame of 15 ft at a height of 6 ft above the top of the keel (Figures 27a, d, 28a).

Starting with these initial findings I experimented with various known historical approaches to designing the midship section to determine a drawing procedure that would yield the same midship shape as *La Belle*'s. The drawing procedure illustrated in Figures 27a–f is essentially the same as one described in La Madeleine's manuscript, *Tablettes de Marine*, from ca. 1712 (Rieth 1996:56–57). In this procedure the shape of the midship frame is mainly defined by two sets of arcs: the lower breadth arcs *CG* and *C'G'* with a common center *D* and the floor arcs *GJ* and *G'J'* with centers *K* and *K'* (Figure 27d).

The complete lower midship section is contained within the rectangle *BB'C'C*, whose width at *BB'* and *CC'* is equal to 15 ft—the maximum beam of the vessel between the outboard faces of the frames (Figure 27a). This width is 1/3 the keel length of 45 ft. The height of the rectangle at *BC* and *B'C'* is 6 ft. This corresponds to the height of the maximum beam above the level of the top of keel at line *BB'* and is 2/5 the beam width (Figure 27a).
In order for point *C* to be at the maximum beam of the vessel, the breadth arc has to be tangent to line *CB* at this point. Therefore the center point of this arc has to be located on line *CC'* which is perpendicular to line *CB*. NEXT

© 2014 TARAS PEVNY

REF: tangencypress.com/essay/1/page/18

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