“Clearly so; the force D B must be exchanged for an equal one B D, or else the angle A B D cannot be equal to the angle D B C; but I will render this fact still farther intelligible by another diagram. Let B, as in the former case, represent the wall, upon which the imperfectly elastic body impinges in the direction A B.--The force will of course be resolved into two others, viz. into D B and F B; the force D B, however, instead of being replaced by the opposite one B D, will now be represented by the shorter line B G; or that of B H or B I, according to the degree of elasticity. If we, therefore, complete the parallelogram, B C, B K, or B M will be the diagonal path of the body; making, as you perceive, the _angle of reflection_ D B C, greater than that of _incidence_ A B D; and where the body is perfectly inelastic, the force D B will be wholly destroyed, and, the force B E alone surviving, the body will be carried along the line B E. I have now,” continued Mr. Seymour, “explained to you the principal laws which govern those forces by which your ball or marbles are actuated. It is true that in practice you cannot expect the results should accurately coincide with the theory, because, in the first place, you cannot obtain marbles that are of equal density and elasticity, and of true figure; and, in the next, there will be obstacles against which it is impossible to guard. The spinning of the marble will also have a material influence on its motion, as we have already discovered. In the game of billiards, where every obstacle is removed, as far as art can assist, the theory and practice are often strangely discordant. But we have dwelt sufficiently upon the subject; we will, therefore, return to the library, where I intend to exhibit an experiment in farther elucidation of the subject of collision.” The party accordingly proceeded on their return. “I hope,” said Mr. Seymour, addressing himself to Mr. Twaddleton, who was walking a few paces before him, “that the maiden ladies have not espied their vicar at a game of marbles; if they should, what a chuckling would there be at their next tea-party!” “A fig for the spinsters!” exclaimed the vicar, as he hastily turned round, and arrested the progress of the party by his gesture. “You really speak, Mr. Seymour, as though it were derogatory to my character to descend from the more austere pursuits to the simple but innocent amusements of youth. Let me remind you, sir, that the Persian ambassadors found Agesilaus, the Lacedæmonian monarch, riding on a stick.”