PREFACE.	7
	million tons of coal is not inconsiderable. The marble of the country, which is just beginning to be developed, bids- fair to compete with that of any other country, .and to revolutionize the civilized world. The marble from California, that from the quarry lately discovered in Pennsylvania, the Leocadia Breccia, the Verde-Antique of Vermont, and the white marble from Canaan, Conn., which is used in the construction of the Fifth wenue Hotel, Madison Square, N. Y.'are referred to as illustrations. Are not the sienites and the granites which have been quarried for the last fifty years, and which have been used in the erection of all our public edifices, really as valuable as Gems ? Few persons were aware, until recently, of the existence of fancy (variegated) marbles in this country ; and Italy, Greece, and Ireland furnish the materials for ornamenting fine houses and cemeteries, beeause our own resources have been overlooked, or not developed. What will be the condition of things fifty years hence, when the fine arts will occupy as prominent a po­sition in this country as in any other, and when wealth and taste will compete with the arts and sciences for the ascendency ? The Almighty has converted the vegetables of the forest into a mineral substance, the animals of the sea into building-stone, and endowed man with the faculty of exploring and developing the hidden treasures of nature, and this faculty will soon render this country independent of all other nations. The principal aim .of the author has been to explain not only the useful, but also the ornamental mineral substances, and such compositions called mosaics as are prepared from them, and he is indebted for much valuable information pertaining to this branch of the subject to the Jury Report of the London Exhibition.