had to settle which was “pulchrius et honorabilius pro ecclesia.”  Donatello’s design was accepted,[74] and the actual glazing was carried out by Bernardo Francesco in eighteen months.[75] The background is a plain blue sky, and the two great figures are the centre of a warm and harmonious composition.  The window stands well among its fellows as regards colour and design, but does not help us to solve difficult problems connected with Donatello’s drawings.  Numbers have been attributed to him on insufficient foundation.[76] The fact is that, notwithstanding the explicit statements of Borghini and Vasari that Donatello and Michael Angelo were comparable in draughtsmanship, we have no authenticated work through which to make our inductions.  A large and important scene of the Flagellation in the Uffizzi,[77] placed within a complicated architectural framework, and painted in green wash, has some later Renaissance features, but recalls Donatello’s compositions.  In the same collection are two extremely curious pen-and-ink drawings which give variants of Donatello’s tomb of John XXIII. in the Baptistery.  The first of them (No. 660) shows the Pope in his tiara, whereas on the tomb this symbol of the Papacy occupies a subordinate place.  The Charity below carries children, another variant from the tomb itself.  The second study (No. 661) gives the effigy of a bareheaded knight in full armour lying to the left, and the basal figures also differ from those on the actual tomb.  These drawings are certainly of the fifteenth century, and even if not directly traceable to Donatello himself, are important from their relation to the great tomb of the Pope, for which Donatello was responsible.  But we have no right to say that even these are Donatello’s own work.  In fact, drawings on paper by Donatello would seem inherently improbable.  Although he almost drew in marble when working in stiacciato, the lowest kind of relief, he was essentially a modeller, rather than a draughtsman.  Leonardo was just the reverse; Michael Angelo was both, but with him sculpture was the art.  Donatello had small sense of surface or silhouette, and we would not 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.