It has been questioned whether the testimony of this Philo is to be depended upon, as few of those who have busied themselves with the pyramids seem to have laid much stress upon it. It seems to us to be worthy of great respect. We do not know when Philo lived, but we know that the casing of the pyramid was still in place, at least in part, during the Middle Ages, because in the time of Abd-ul-Latif it had almost its original height, and its ascent was still very difficult.[210] On the other hand we have proofs that, although the author of the Seven Wonders of the World may have written more in the tone of a rhetorician than of an eyewitness of the wonders which he describes, he took some of his information from excellent sources. In fact with the exception of Pliny, he is the only ancient writer who gives us an approximately true statement of the length of the base line of Cheops' Pyramid. While the measurements of other writers are very far from accurate, the figure given by Philo is only 16 feet 6 inches in excess of the truth. The idea of decorating such an expanse of surface with varied colour was quite in accordance with Egyptian taste. They loved polychromatic ornaments; they covered every available surface with the gayest hues; they delighted in the juxtaposition of the most brilliant tones. They could hardly think of covering such an immense surface with paint, and as it was necessary, in any case, to cover it with a smooth casing, it would be no more difficult to employ many kinds of stone than one. They would thus obtain a kind of gigantic mosaic which may perhaps have been heightened in effect by the use of gold. We know that the pyramidion of an obelisk was frequently gilded, and it is probable enough that similar means were sometimes taken, in the case of the more magnificent and carefully finished pyramids, to draw the eye to their topmost stone and thus to add to the impression made by their height. No more fitting adornment could be imagined for the sharp peak of a pyramid rising nearly five hundred feet into the pure blue of an Egyptian sky.