How long the pencil continued only to assist, when it began to engross and when it at last entirely supplanted the cestrum, cannot in the perplexity of accidental report be ascertained. Apollodorus in the 93d Olymp. and Zeuxis in the 94th, are said to have used it with freedom and with power. The battle of the Lapithæ and the Centaurs, which according to Pausanias, Parrhasius painted on the shield of the Minerva of Phidias, to be chased by Mys, could be nothing but a monochrom, and was probably designed with the cestrum, as an instrument of greater accuracy.[6] Apelles and Protogenes, nearly a century afterwards, drew their contested lines with the pencil; and that alone, as delicacy and evanescent subtlety were the characteristic of those lines, may give an idea of their mechanic excellence. And yet in their time the _diagraphic_ process,[7] which is the very same with the _linear_ one we have described, made a part of liberal education. And Pausias of Sicyon, the contemporary of Apelles, and perhaps the greatest master of composition amongst the ancients, when employed to repair the decayed pictures of Polygnotus at Thespiæ, was adjudged by general opinion to have egregiously failed in the attempt, because he had substituted the pencil to the cestrum, and entered a contest of superiority with weapons not his own. Here it might seem in its place to say something on the Encaustic method used by the ancients; were it not a subject by ambiguity of expression and conjectural dispute so involved in obscurity that a true account of its process must be despaired of: the most probable idea we can form of it is, that it bore some resemblance to our oil-painting, and that the name was adopted to denote the use of materials, inflammable or prepared by fire, the supposed durability of which, whether applied hot or cold, authorised the terms ἐνεκαυσε and _inussit_.