The river at Amboise: currents around an island
A bird's-eye study of the Loire's contrary flows, with untranscribed plans on the facing folio
A study of the river at Amboise. Folio 269r bears a large bird's-eye drawing of the river dividing around an island, its currents rendered in fine flow-lines, with notes explaining that the water stands higher inside the embankment b d than outside it. Leonardo traces the course through a b c d, its doubling back upstream through the channel d e b f against the embankment d b, and its turn downward through f l g h n m to rejoin the main stream at K n; when the river is in flood it runs all one way, overtopping the embankment b d. The facing folio 264v carries untranscribed square ground-plans, a domed structure, and stair plans, and a British Museum stamp appears on the sheet.
On this page
River standing higher inside its embankment than outside
At Amboise the river runs higher within the embankment b d than on the outer side of that same embankment.
Contrary currents around the island of Amboise
The river passes through a b c d and, past the bridge c d, flows back upstream through the channel d e b f against the embankment d b, which stands between the two contrary motions. It then turns down through f l g h n m and rejoins the stream it left at K n, forming K m r t; only in flood does it run wholly one way, over the embankment b d.
Bird's-eye plan of the river channels around the island
The right folio is drawn as a plan from above: the river split into two long limbs enclosing the island of Amboise, the currents traced with dense flow-lines and lettered from a through m, K, r and t to key the accompanying text.
Untranscribed ground-plans on the facing folio
The left folio (264v) bears square ground-plans with central features, a small domed structure, and stair plans, none of which is transcribed in the source edition; they are noted here only as further, untranscribed drawing on the sheet.