The master of the ill-fated brig had calculated his latitude correctly; he knew the rate of his vessel's speed; the compass had showed him the parallel on which to steer. These premises ought to have secured a safe conclusion; and so they would, but for an unrecognised power that vitiated all; he was not aware of the silent and secret current, that was every hour setting him to the south of his supposed latitude. The path of Uranus had been calculated by the astronomers with scrupulous care, and every known element of disturbance had been considered; not by one, but by many. But for the fact that the planet had been previously seen in positions quite inconsistent with such a path, it would have been set down as beyond controversy correct. Stubborn fact, however, would not give way; and hence the dilemma, till Le Verrier suggested the unseen antagonist. I venture to suggest in the following pages an element, hitherto overlooked, which disturbs the conclusions of geologists respecting the antiquity of the earth. Their calculations are sound on the recognised premises; _but they have not allowed for the Law of Prochronism in Creation_. The enunciation of this principle will lie in a nut-shell; the reader will find it at p.124; or p.347. All the rest of the book is illustration. I do not claim originality for the thought which I have here endeavoured to work out. It was suggested to me by a Tract, which I met with some dozen years ago, or more; the title of which I have forgotten: I am pretty sure it was anonymous, but it was published by Campbell, of 1, Warwick Square. Whether it is still in print I do not know; I never saw another copy. If the author is alive, and if he should happen to cast his eye on this volume, he will doubtless recognise his own bantling, and accept this my acknowledgment. The germ of the argument, however, I have found, since these pages were written, in "The Mineral and Mosaical Geologies," of Granville Penn (1822). The state of physical science when he wrote did not enable him to press the argument to a demonstration, as I have endeavoured to do; for he could not refer to structural peculiarities as sensible records of past processes, _inseparable from newly created organisms_. I would not be considered as an opponent of geologists; but rather as a co-searcher with them after that which they value as highly as I do, TRUTH. The path which I have pursued has led me to a conclusion at variance with theirs. I have a right to expect that it be weighed; let it not be imputed to vanity if I hope that it may be accepted.