"4. The Chalk was, by some change of marine currents, washed away, or degraded, [_i. e._ worn away under the atmosphere by the weather and casualties, a process slow almost beyond description,] and the solid flints and fossils [thus detached from their imbeddings], were rolled into shingles. "5. Afterwards, these shingles were covered up, and buried under Tertiary deposits. "In this way of interpretation, a section of _a few perpendicular feet_ indicates a LONG lapse of time, and the co-ordinate fact of the entire change of organic types, between the beds above and those below, falls in with the preceding inference, and shows the lapse of time to have been VERY LONG."[50] IV. THE CROSS-EXAMINATION. "When the fact itself cannot be proved, that which comes nearest to the proof of the fact is the proof of the circumstances that necessarily and usually attend such facts; and _these are called presumptions, and not proofs_, for they stand instead of the proofs of the fact, till the contrary be proved."--GILBERT; LAW OF EVIDENCE. Such, then, is the evidence for the macro-chronology. I hope I have summed it up fairly; of course, many details I have been forbidden to adduce by want of space, but they would have been of the same kind as those brought forward. I am not conscious of having in any degree cushioned, or concealed, or understated a single proof which would have helped the conclusion. A mighty array of evidence it certainly is, and such as appears at first sight to compel our assent to the sequent claimed for it. I must confess that I have no sympathy with the _reasonings_ of those, however I honour their design, who can find a sufficient cause for these phenomena in the natural operations of the Antediluvian centuries, or in the convulsion that closed them. But is there no other alternative? Am I compelled to accept the conclusions drawn from the phenomena thus witnessed unto, as undeniable facts, since they refuse to be normally circumscribed within the limits of the historic period? I verily believe there is another, and a perfectly legitimate solution. My first business is to examine, and, if I can, to disprove this testimony. If I can show the witness to be liable to error; if I can adduce a principle which invalidates all his proofs; if I can make it undeniably manifest that, in a case precisely parallel, similar conclusions, deduced from exactly analogous phenomena, would be notoriously false; if I can do this, I think I have a right to demand that the witness be bowed out of court, as perfectly nugatory and worthless _in this cause_.