A trabocco is four braccia, and one mile is three thousand of the
said braccia. Each braccio is divided into 12 inches; and the water
in the canals has a fall in every hundred trabocchi of two of these
inches; therefore 14 inches of fall are necessary in two thousand
eight hundred braccia of flow in these canals; it follows that 15
inches of fall give the required momentum to the currents of the
waters in the said canals, that is one braccio and a half in the
mile. And from this it may be concluded that the water taken from
the river of Ville-franche and lent to the river of Romorantin
will..... Where one river by reason of its low level cannot flow
into the other, it will be necessary to dam it up, so that it may
acquire a fall into the other, which was previously the higher.

The eve of Saint Antony I returned from Romorantin to Amboise, and
the King went away two days before from Romorantin.

>From Romorantin as far as the bridge at Saudre it is called the
Saudre, and from that bridge as far as Tours it is called the Cher.

I would test the level of that channel which is to lead from the
Loire to Romorantin, with a channel one braccio wide and one braccio
deep.

[Footnote: Lines 6-18 are partly reproduced in the facsimile on p.
254, and the whole of lines 19-25.

The following names are written along the rivers on the larger
sketch, _era f_ (the Loire) _scier f_ (the Cher) three times. _Pote
Sodro_ (bridge of the Soudre). _Villa francha_ (Villefranche)
_banco_ (sandbank) _Sodro_ (Soudre). The circle below shows the
position of Romorantin. The words '_orologio del sole_' written
below do not belong to the map of the rivers. The following names
are written by the side of the smaller sketch-map:--_tors_ (Tours),
_Abosa_ (Amboise) _bres_--for Bles (Blois) _mo rica_ (Montrichard).
_Lione_ (Lyons). This map was also published in the 'Saggio'
(Milano, 1872) Pl. XXII, and the editors remark: _Forse la linia
retta che va da Amboise a Romorantin segna l'andamento proposto d'un
Canale, che poi rembra prolungarsi in giu fin dove sta scritto
Lione._

M. Ravaisson has enlarged on this idea in the Gazette des Beaux Arts
(1881 p. 530): _Les traces de Leonard permettent d'entrevoir que le
canal commencant soit aupres de Tours, soit aupres de Blois et
passant par Romorantin, avec port d'embarquement a Villefranche,
devait, au dela de Bourges, traverser l'Allier au-dessous des
affluents de la Dore et de la Sioule, aller par Moulins jusqu' a
Digoin; enfin, sur l'autre rive de la Loire, depasser les monts du
Charolais et rejoindre la Saone aupres de Macon._ It seems to me
rash, however, to found so elaborate an hypothesis on these sketches
of rivers. The slight stroke going to _Lione_ is perhaps only an
indication of the direction.--With regard to the Loire compare also
No. 988. l. 38.]