There is, indeed, one exception in this very neighborhood, to which we may now naturally turn. The traveller who has wondered at the huge blocks of the Propylæa and the Parthenon, and who has noticed the exquisite quality of the stone, and the perfect smoothness which it has preserved to the present day, will naturally desire to visit the quarry on Pentelicus from which it was brought. The marble of Paros is probably the only stone found superior to it for the purposes of sculpture. It is, however, harder and of larger grain, so that it must have been more difficult to work. Experts can tell the difference between the two marbles, but I confess that, though M. Rousopoulos endeavored to teach it to me from specimens in the Acropolis Museum, I was unable to attain a clear knowledge of the distinction. The large blocks of Pentelican marble, however beautiful and fine in grain, seem not unfrequently to have contained flaws, and possibly the ascertaining of this defect may of old have been one of the most difficult duties of the architect. It is supposed to have been done by sounding the block with a hammer, a process which the Greeks would call _κωδωνίζειν_. There are at present, close to the east front of the Parthenon, several of these rejected blocks, and the lapse of ages has brought out the flaw visibly, because damp has had time to penetrate the stone, and stain its pure whiteness with a dark seam. But when it came fresh from its native bed, and was all pure white, I presume the difficulty must have been considerable. Possibly these blocks on the Parthenon were injured in their transit, and left the quarries in sound condition. For in going up the steep road to these quarries, in more than one place a similar great block will be found tumbled aside, and left lying at the very spot where we may suppose some accident to have happened to crack it. This road, which in its highest parts has never been altered, is a steep descent, rudely paved with transverse courses of stone, like steps in pattern, and may have had wooden slides laid over it, to bring down the product of the quarries to the valley. It is well worth while going up for a night to the fine monastery not far off, where there is ample shade of waving trees and plenty of falling water, in the midst of steep slopes wooded with the fir—a cool and quiet retreat in the fierce heat of summer.(75) From this place to the quarries is less than an hour’s walk. The moderns still draw stone from them, but far below the spots chosen by the ancients; and, of course, the remains of the old industry are on an infinitely grander scale.