Even a single deposit of this sort might prove of enormous value to the race at some critical period of its history. But the probability is that the good work would not end with one deposit. From age to age this and other nations might repeat the experiment, commemorating in this way important epochs in their history. The fashion once set might easily become a permanent feature of all great national celebrations. The cost would be comparatively small: a penny contribution from each of the visitors to the Philadelphia Exhibition, for example, would have been quite sufficient to provide for a memorial of our first Centennial year that would have carried an imperishable picture of the civilization of the day to the end of--our first millennium, at least; and we may safely infer that, whatever may be the condition of the world at that not very remote epoch, a memorial of that sort would be something worth having. As we have intimated, the custom might easily become general, so that in the course of ages the earth would become dotted with such repositories of art and learning. Then, come what might to humanity--whatever might be the ups and downs of nations--whatever moral, social, or intellectual advances mankind might make--whatever lapses or disasters might befall them--it could hardly happen that a knowledge of any considerable period of human history, or the advantage of any worthy human achievement, could ever be permanently blotted out and lost. It is true that "posterity" has never done anything of the sort for us. It is true that "posterity" may have no valid claim on us for such a legacy. But we might venture to make "posterity" a present! It would not cost us much, and it might turn out to be immensely valuable and useful to some far future age. * * * * * THE LOST ARTS IN NEW YORK. While the objects of ancient art contained in the Castellani collection, recently placed on exhibition in the Metropolitan Museum of Art in this city, are individually of great rarity and archaeological value, they derive additional importance from the fact that, viewed conjunctively as a collection, they represent connected histories of two great industrial arts extending over many centuries. Both in the work of the goldsmith and of the potter, we are enabled to trace progress from the earliest stages up to a period when the greatest skill was attained, and even subsequently into the era of decadence. In both industries, we find that ancient and mediaeval workmen possessed knowledge which we do not possess; and among Signor Castellani's treasures may be seen handiwork which is the embodiment of two lost arts, the secrets of which the modern world, with all its infinitely superior wisdom, has not yet rediscovered.