[71] Herzfeld, p. 292.
[72] Vasari, translated by Schorn, 1843.
[73] Ebenda, p. 39.
[74] Concerning these letters and the combinations connected with them see Müntz, l. c., p. 82; for the wording of the same and for the notices connected with them see Herzfeld, l. c., p. 223.
[75] Besides, he lost some time in that he even made a drawing of a braided cord in which one could follow the thread from one end to the other, until it formed a perfectly circular figure; a very difficult and beautiful drawing of this kind is engraved on copper, in the center of it one can read the words: "Leonardus Vinci Academia" (p. 8).
[76] This criticism holds quite generally and is not aimed at Leonardo's biographers in particular.
[77] Seidlitz II, p. 271.
[78] La natura è piena d'infinite ragionè che non furono mai in isperienza, M. Herzfeld, l. c. p. II.