The useful arts comprehend not only those that lie next to instinct, as agriculture, building, weaving, &c., but also navigation, practical chemistry, and the construction of all the grand and delicate tools and instruments by which man serves himself: as language, the watch, the ship, the decimal cipher; and also the sciences, so far as they are made serviceable to political economy. When we reflect on the pleasure we receive from a ship, a railroad, a dry-dock; or from a picture, a dramatic representation, a statue, a poem, we find that these have not a quite simple, but a blended origin. We find that the question, What is Art? leads us directly to another,--Who is the artist? and the solution of this is the key to the history of Art. I hasten to state the principle which prescribes, through different means, its firm law to the useful and the beautiful arts. The law is this. The universal soul is the alone creator of the useful and the beautiful; therefore, to make anything useful or beautiful, the individual must be submitted to the universal mind. In the first place, let us consider this in reference to the useful arts. Here the omnipotent agent is Nature; all human acts are satellites to her orb. Nature is the representative of the universal mind, and the law becomes this,--that Art must be a complement to nature, strictly subsidiary. It was said, in allusion to the great structures of the ancient Romans,--the aqueducts and bridges,--that “their Art was a Nature working to municipal ends.” That is a true account of all just works of useful art. Smeaton built Eddystone Light-house on the model of an oak-tree, as being the form in nature best designed to resist a constant assailing force. Dollond formed his achromatic telescope on the model of the human eye. Duhamel built a bridge by letting in a piece of stronger timber for the middle of the under surface, getting his hint from the structure of the shin-bone.