There exists too, or did exist, a Horse that was painted by him for a pictorial contest; as to the merits of which, Apelles appealed from the judgment of his fellow-men to that of the dumb quadrupeds. For, finding that by their intrigues his rivals were likely to get the better of him, he had some horses brought, and the picture of each artist successively shown to them. Accordingly, it was only at the sight of the horse painted by Apelles that they began to neigh; a thing that has always been the case since, whenever this test of his artistic skill has been employed. He also painted a Neoptolemus[2034] on horse-back, fighting with the Persians; an Archeläus,[2035] with his Wife and Daughter; and an Antigonus on foot, with a cuirass on, and his horse led by his side. Connoisseurs in the art give the preference, before all other works of his, to his paintings of King Archeläus on horseback, and of Diana in the midst of a throng of Virgins performing a sacrifice; a work in which he would appear to have surpassed the lines[2036] of Homer descriptive of the same subject. He also portrayed some things, which in reality do not admit of being portrayed—thunder, lightning, and thunderbolts, in pictures which are known by the respective names of Bronte, Astrape, and Ceraunobolia. His inventions, too, in the art of painting, have been highly serviceable to others; but one thing there was in which no one could imitate him. When his works were finished, he used to cover them with a black varnish, of such remarkable thinness, that while by the reflection it gave more vivacity to the colours, and preserved them from the contact of dust and dirt, its existence could only be detected by a person when close enough to touch it.[2037] In addition to this, there was also this other great advantage attending it: the brightness of the colours was softened thereby, and harmonized to the sight, looking as though they had been viewed from a distance, and through a medium of specular-stone;[2038] the contrivance, by some indescribable means, giving a sombreness to colours which would otherwise have been too florid.