"Lord! sir," said he, "I am myself Jack the Darter." He had a roll of brown paper in his hand, which he unfolded, and soon produced a bundle of the light deal sticks which he had the power of darting to such a distance. He readily consented to gratify my curiosity; and after he had thrown some of them to a prodigious height, I asked him to throw some of them horizontally. At the first trial he threw one of them eighty yards with great ease. I observed that he coiled a small string round the stick, by which he gave it a rotary motion that preserved it from altering its course; and at the same time it allowed the arm which threw it time to exercise its whole force. If anything be simply thrown from the hand, it is clear that it can acquire no greater velocity than that of the hand that throws it; but if the body that is thrown passes through a greater space than the hand, whilst the hand continues to communicate motion to the body to be impelled, the body will acquire a velocity nearly double to that of the hand which throws it. The ancients were aware of this; and they wrapped a thong of leather round their javelins, by which they could throw them with additional violence. This invention did not, I believe, belong to the Greeks; nor do I remember its being mentioned by Homer or Xenophon. It was in use among the Romans, but at what time it was introduced or laid aside I know not. Whoever is acquainted with the science of projectiles will perceive that this invention is well worthy of their attention. A ONE-WHEELED CHAISE.