The pasteboard was produced, and Mr. Seymour described upon it a spiral, similar to that which is represented in the annexed figure. The spiral was cut out, and extended, by raising the centre above the first revolution. It was then suspended upon a small spit of iron, which had been previously prepared; by applying the centre or summit of its spiral to its point. The whole was now placed on the top of a warm stove, (the application of a lamp would have answered the same purpose,) and the machine, to the great delight and astonishment of the children, soon put itself in motion, and turned without the assistance of any apparent agent. The agent, however, in this case, was the air, which being rarefied by the contact of a warm body, ascended, and thus produced a current. The accompanying sketch may render this experiment more intelligible to the reader.
The vicar observed that, to him, the experiment was perfectly novel; although he remembered having seen what he now supposed must have been a similar contrivance, but which, until that moment, he had always considered as the effect of clockwork.
“And what might that have been?” asked Mr. Seymour.
“The revolution of a serpent, which I noticed in several windows in London, during a late illumination.”
“Undoubtedly; it was nothing more than a spiral, so painted as to resemble that reptile, and which owed its motion to the action of air heated by a lamp placed beneath it.”
“Now, then,” exclaimed the vicar, “let us direct our attention to the bow and arrow; see the present I have provided for you, Tom!”
So saying, the worthy clergyman produced a bow and a number of arrows, together with a target; which, at his desire, had been sent from London.
“I think,” observed Mr. Seymour, “that you should accompany your gift with some account of archery, or the art and exercise of shooting with the bow and arrow.”
“That will I readily do,” replied Mr. Twaddleton; who accordingly proceeded as follows:--