Masonry arch study with weights of a pillar and tiburio
A great vaulted arch on a buttressed pier, with calculations for the weight of a pillar and a crossing-tower
A large drawing shows a great masonry arch or half-vault of coursed stone voussoirs springing from a heavy buttressed pier, with pinnacles above. In the lower-left corner Leonardo works a chain of multiplications to find the weight of a pillar and of the tiburio (crossing-tower), reaching 576,000 for a pillar of nine heads and a much larger figure for the tiburio. A glued paper slip at the top opens a maxim beginning 'Every heavy thing…'. Further faint annotations lie beyond those transcribed.
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Great vaulted arch on a buttressed pier
The sheet is filled by a large arch of coursed stone voussoirs rising over a massive buttressed pier crowned with pinnacles, a study of the structure and coursing of a monumental vault. No caption describes the drawing, so it is read from the image.
Weight of the pillar and of the tiburio
A column of multiplications in the lower left builds up to 576,000, labelled the weight of the pillar of nine heads, and, multiplied further by 8, to 4,608,000 given as the weight of the tiburio (crossing-tower). The figures estimate the loads of the masonry.
'Every heavy thing…'
A rectangle of paper glued at the top of the sheet begins a proposition on weight, 'Every heavy thing…', framing the calculations below as a study of how the load of the structure bears down.