[Footnote:  By the side of this text there is an indistinct sketch, resembling that given under No.973.  On the bank is written the word Casace.  There then follows in the original a passage of 12 lines in which the consequences of the windings of the river are discussed.  A larger but equally hasty diagram on the same page represents the shores of the Arno inside Florence as in two parallel lines.  Four horizontal lines indicate the bridges.  By the side these measures are stated in figures:  I. (at the Ponte alla Carraja):  230—­largho br. 12 e 2 di spoda e 14 di pile e a 4 pilastri; 2. (at the Ponte S. Trinita); l88—­largho br. 15 e 2 di spode he 28 di pilastri for delle spode e pilastri so 2; 3. (at the Ponte vecchio); pote lung br. 152 e largo; 4. (at the Ponte alle Grazie):  290 ellargo 12 e 2 di spode e 6 di pili.

There is, in MS. W. L. 2l2b, a sketched plan of Florence, with the following names of gates:  Nicholo—­Saminiato—­Giorgo—­Ghanolini—­Porta San Fredian —­Prato—­Faenza—­Ghallo—­Pinti—­Giustitia.]

1005.

The ruined wall is 640 braccia; 130 is the wall remaining with the mill; 300 braccia were broken in 4 years by Bisarno.

1006.

They do not know why the Arno will never remain in a channel.  It is because the rivers which flow into it deposit earth where they enter, and wear it away on the opposite side, bending the river in that direction.  The Arno flows for 6 miles between la Caprona and Leghorn; and for 12 through the marshes, which extend 32 miles, and 16 from La Caprona up the river, which makes 48; by the Arno from Florence beyond 16 miles; to Vico 16 miles, and the canal is 5; from Florence to Fucechio it is 40 miles by the river Arno.

56 miles by the Arno from Florence to Vico; by the Pistoia canal it is 44 miles.  Thus it is 12 miles shorter by the canal than by the Arno.

[Footnote:  This passage is written by the side of a map washed in Indian ink, of the course of the Arno; it is evidently a sketch for a completer map.

These investigations may possibly be connected with the following documents. Francesco Guiducci alla Balia di Firenze.  Dal Campo contro Pisa 24 Luglio 1503 (Archivio di Stato, Firenze, Lettere alla Balia; published by J. GAYE, Carteggio inedito d’Artisti, Firenze 1840, Tom.  II, p. 62):  Ex Castris, Franciscus Ghuiduccius, 24. Jul. 1503. Appresso fu qui hieri con una di V. Signoria Alexandro degli Albizi insieme con Leonardo da Vinci et certi altri, et veduto el disegno insieme con el ghovernatore, doppo molte discussioni et dubii conclusesi che l’opera fussi molto al proposito, o si veramente Arno volgersi qui, o restarvi con un canale, che almeno vieterebbe che le colline da nemici non potrebbono essere offese; come tucto referiranno loro a bocha V. S.

And, Archivio di Stato, Firenze, Libro d’Entrata e Uscita di cassa de’ Magnifici Signori di luglio e agosto