Of such observations on proportion it would be easier to continue a long series than to make them intelligible or useful without actual demonstration or figures. From Vitruvius with his commentators, and Lionardo da Vinci, to Albert Durer, Lomazzo, and Jerome Cardan, from the corrected measurements of Du Fresnoy and De Piles, to Watelet, Winkelman, and Lavater, it would be easy to show that the mass of variance, peculiarity, and contradiction, greatly overbalances the coincidence of experiment and measure. "The descriptions of the proportions of the human frame," says Mengs, "are infinite, but seldom agree among themselves. Some are too obscure to give the artist a clear idea; some have too much limited the combinations which might produce, or are capable of, proportions homogeneously uniform: others, on the contrary, have, like Albert Durer, displayed a great quantity and variety of proportions, to little purpose for any one who should not choose to imitate his taste. The ordinary method is that of dividing the figure into a fixed number of heads or faces; but this division is of more use to the sculptor than the painter, who never can see the just size of the head, because perspective hides at least a third of the upper fourth; nor does the breadth of the limbs, in painting, admit of sculpture measure, as they would appear meagre and scanty on a flat surface, in comparison of the mass they circumscribe in perspective; because the habit of looking at objects with both eyes swells their mass beyond its just diameter, in reality as well as in sculpture. This difference of limbs the ancients observed in their best basso-relievoes; they exceed in volume the limbs of their statues. Such are the forms of the sacrificing group in the gardens of the Medicean Villa at Rome, represented in the Admiranda of Santes Bartoli, and imitated by Raffaello in the Cartoon of the Sacrifice at Lystra." The painter is infinitely more in want of variety than the sculptor, and consequently cannot submit to the same restriction of rule. Raffaello, who in a certain sense did no more than multiply the antique style of the second order, uniting it with a certain air of truth not within the reach of sculpture, whether from rule or taste, made use of every kind of proportion without a seeming predilection for any. There are figures of his which have little more than six heads and a half: such as the St. Peter in the Cartoon of the Temple Gate; a proportion insufferable in any other painter but Raffaello.