Interest. Interest, is the money paid for the loan of a sum, denominated the principal, for a given time according to a fixed rate. Interest is distinguished as simple and compound. Simple interest is that which is paid for the principal, or sum lent, at a certain rate or allowance made by law or agreement of parties, whereby so much as $5, $6, or any other sum is paid for $100 lent out for a year; and the same amount of interest per cent, per annum for any longer time. Compound interest is that which accumulates when the simple interest is added to the principal, and the subsequent interest calculated on the constant accumulation. In this manner the principal nearly doubles every fourteen years. The accumulation of money when placed at compound interest, after a certain number of years, is exceedingly rapid, and, in some cases, truly astonishing. One penny put out at five per cent, compound interest, at the birth of Christ, would, in 1810, have amounted to a sum exceeding in value 357,000,000 of solid globes of standard gold, each in magnitude as large as this earth.