CHAPTER III.
Motion--absolute and relative.--Uniform, accelerated, and retarded Velocity.--The times of Ascent and Descent are equal.--Vis inertiæ.--Friction.--Action and Reaction are equal and in opposite directions.--Momentum defined and explained.--The Three Great Laws of Motion.
“The table-cloth is removed,” cried Tom, as he cast a sly glance through the open window of the dining-room.
“It is, my boy,” replied Mr. Twaddleton; “Diffugere nives, as the poet has it.”
“Et redeunt jam gramina campis,” added Mr. Seymour, archly, as he pointed to the green cloth with which the table was covered.
“Et decrescentia flumina,” continued the vicar, with a smile; “but, psha! enough of wine and quotation. Come, let us join the children.”
Mr. Twaddleton, accompanied by Mr. and Mrs. Seymour, and Louisa, rose from the table, and proceeded to the lawn.
“The gravitation of Tom’s ball,” said Mr. Seymour, “furnished an ample subject for our morning’s diversion; let us try whether its other motions will not suggest further objects of enquiry.”
“I well remember,” observed Louisa, “that Mrs. Marcet extols that apple, the fall of which attracted the notice of Sir Isaac Newton, above all the apples that have ever been sung by the poets: and she declares, that the apple presented to Venus by Paris; the golden apples by which Atalanta won the race; nay, even the apple which William Tell shot from the head of his own son, cannot be brought into comparison with it.”
“Well said! Mrs. Marcet,” exclaimed Mr. Seymour; “upon my word, had the mother of mankind used but half such eloquence in praise of an apple, we cannot wonder at its influence.”