The river Loire at Amboise.

The river is higher within the bank _b d_ than outside that bank.

The island where there is a part of Amboise.

This is the river that passes through Amboise; it passes at _a b c
d_, and when it has passed the bridge it turns back, against the
original current, by the channel _d e_, _b f_ in contact with the
bank which lies between the two contrary currents of the said river,
_a b_, _c d_, and _d e_, _b f_. It then turns down again by the
channel _f l_, _g h_, _n m_, and reunites with the river from which
it was at first separated, which passes by _k n_, which makes _k m_,
_r t_. But when the river is very full it flows all in one channel
passing over the bank _b d_. [Footnote: See Pl. CXV. Lines 1-7 are
above, lines 8-10 in the middle of the large island and the word
_Isola_ is written above _d_ in the smaller island; _a_ is written
on the margin on the bank of the river above 1. I; in the
reproduction it is not visible. As may be seen from the last
sentence, the observation was made after long study of the river's
course, when Leonardo had resided for some time at, or near,
Amboise.]