expect him to commit his ideas to paper, just as Nollekens,[78] who
drew so badly that he finally gave up drawing, and limited himself to
modelling instead--turning the clay round and round and observing it
from different aspects, thus employing a tactile in place of a
pictorial medium. Canova also trusted chiefly to the plastic sense to
create the form. But Donatello must nevertheless have used pen and ink
to sketch the tombs, the galleries, the Roman tabernacle, and similar
works. It is unfortunate that none of his studies can be identified.
There is, however, one genuine sketch by Donatello, but it is a sketch
in clay. The London Panel[79] was made late in life, when Donatello
left a considerable share to his assistants. It is therefore a
valuable document, showing Donatello's system as regards his own
preliminary studies and the amount of finishing he would leave to
pupils. We see his astonishing plastic facility, and the ease with
which he could improvise by a few curves, depressions and prominences
so complex a theme as the Flagellation, or Christ on the Cross. It
is a marvel of dexterity.

[Footnote 64: Domopera archives, 12, viii., 1412.]

[Footnote 65: _Ibid._, 31, xii., 1407.]

[Footnote 66: Padua, 3, iv., 1443.]

[Footnote 67: When working at Pisa in 1427. See Centofanti, p. 4.]

[Footnote 68: Commission for bronze Baptist for Ancona, 1422.]

[Footnote 69: Contract in Orvieto archives, 10, ii., 1423.]