Mr. Seymour then placed the pith-ball at the end of the pipe, and, inserting its other extremity in his mouth, blew out the ball, which immediately rose in the air, and continued to float about for several seconds: he then drew in his breath, and caught it with much address on one of its points; and in this manner, alternately floating and catching it, did he continue to delight the wondering group for several minutes. Tom received the tube and ball from the hand of his father, and soon succeeded in playing with it. Observe, gentle reader, the address with which the boy manages it. [Illustration: Tom keeping the pith-ball aloft by blowing into the tube.] “This reminds me of my pea-shooter,” said Tom, as he removed the tube from his mouth, “with which I have often shot a pea across the play-ground.” “Exactly; and you will now understand the nature of the force by which your pea was projected. The air blown from the lungs, gains such momentum from the contracted channel in which it flows, as to impart considerable velocity to the pea placed within the influence of its current.” Mrs. Seymour observed, that she had lately read in Waterton’s “Wanderings in South America,” a very interesting account of the Indian blow-pipe, which the natives of Guiana employ as an engine for projecting their poisoned arrows, and which owes its power to the principle of which Mr. Seymour had just spoken, and its unerring accuracy to the skilful address of the Indian who uses it.(10) “Mr. Seymour,” said the vicar, “I much like your experiment with the pith-balls; but do tell me the use of the pins that are passed through them.” “They are not absolutely necessary for the success of the experiment: indeed, I ought to have stated, that their only use is to ensure the elevation of the ball to a certain distance above the orifice of the tube, before it is set adrift.” “‘_Ne turbata volent rapidis ludibria ventis_,’ as Virgil has it. I duly appreciate the contrivance; but if the ball was set off at a distance from the orifice, such an expedient would be unnecessary.” “Certainly,” answered Mr. Seymour; “I will soon convince you that, under the condition you propose, the pins are not essential.” So saying, he placed the tube in his mouth, and by carefully holding the ball at a distance of about half an inch from its orifice, he was enabled to consign it at once to a continuous and steady stream of air, which can never be commanded at the point from which the air issues; and he thus succeeded in sustaining the ball in motion, in the same manner as he did in the preceding experiment. “We will now proceed to the orchard,” said Mr. Seymour, “where I have prepared another pleasing exhibition of a similar description.”