This artist was, sometimes, visited by Rasselas, who was pleased with every kind of knowledge, imagining that the time would come, when all his acquisitions should be of use to him in the open world. He came one day to amuse himself in his usual manner, and found the master busy in building a sailing chariot: he saw that the design was practicable upon a level surface, and, with expressions of great esteem, solicited its completion. The workman was pleased to find himself so much regarded by the prince, and resolved to gain yet higher honours. "Sir," said he, "you have seen but a small part of what the mechanick sciences can perform. I have been long of opinion, that instead of the tardy conveyance of ships and chariots, man might use the swifter migration of wings; that the fields of air are open to knowledge, and that only ignorance and idleness need crawl upon the ground." This hint rekindled the prince's desire of passing the mountains: having seen what the mechanist had already performed, he was willing to fancy that he could do more; yet resolved to inquire further, before he suffered hope to afflict him by disappointment. "I am afraid," said he to the artist, "that your imagination prevails over your skill, and that you now tell me rather what you wish, than what you know. Every animal has his element assigned him: the birds have the air, and man and beasts the earth."--"So," replied the mechanist, "fishes have the water, in which, yet, beasts can swim by nature, and men by art. He that can swim needs not despair to fly: to swim is to fly in a grosser fluid, and to fly is to swim in a subtler. We are only to proportion our power of resistance to the different density of matter through which we are to pass. You will be, necessarily, upborne by the air, if you can renew any impulse upon it, faster than the air can recede from the pressure." "But the exercise of swimming," said the prince, "is very laborious; the strongest limbs are soon wearied; I am afraid, the act of flying will be yet more violent, and wings will be of no great use, unless we can fly further than we can swim."