Studies of arched and triangular trusses for wide spans
Four framed structures with span notes: single vs. double member, 40 braccia
The sheet stacks four structural frameworks: two wide semicircular arches braced with radiating and triangulated internal members, and below them two triangular gable trusses of king-post type. Brief captions attach dimensions and construction notes to each: the top figure is marked 'of a single piece / double', while the three lower figures each carry a span of 40 braccia. The drawings read as studies of timber trussing and arch centering for large spans such as roofs or bridges.
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Wide braced arch, single or double member
The uppermost figure is a broad semicircular arch whose interior is filled with radiating lines and a triangulated web springing from a low center. The caption notes whether the frame is made 'of a single piece' or 'double', i.e. with a compound rather than a single tie or rib.
Second arch, 40-braccia span
A second semicircular arch, similarly triangulated, is labelled with a span of 40 braccia. The subdivided web distributes the load of the wide opening down to the springing points and central node.
Triangular king-post truss, 40 braccia
The first of the two lower figures is a shallow triangular truss with a central raised member and diagonal struts, again spanning 40 braccia. It reads as a roof or bridge truss carrying its load to the two end supports.
Lower triangular truss, 40 braccia
The bottom figure is a comparable triangular truss with diagonal bracing between tie and rafters, once more marked at 40 braccia. It varies the internal member arrangement of the truss above it.