From whatever I have been able to observe up to this time the series of strata which form the visible crust of the earth appear to me classified in four general and successive orders. These four orders can be conceived to be four very large strata, as they really are, so that wherever they are exposed, they are disposed one above the other, always in the same order.

GEOLOGY, n. The science of the earth's crust —to which, doubtless, will be added that of its interior whenever a man shall come up garrulous out of a well. The geological formations of the globe already noted are catalogued thus: The Primary, or lower one, consists of rocks, bones of mired mules, gas-pipes, miners' tools, antique statues minus the nose, Spanish doubloons and ancestors. The Secondary is largely made up of red worms and moles. The Tertiary comprises railway tracks, patent pavements, grass, snakes, mouldy boots, beer bottles, tomato cans, intoxicated citizens, garbage, anarchists, snap-dogs and fools.

Some drill and bore
The solid earth, and from the strata there
Extract a register, by which we learn,
That he who made it, and reveal'd its date
To Moses, was mistaken in its age.

The sediments of the past are many miles in collective thickness: yet the feeble silt of the rivers built them all from base to summit.

The successive series of stratified formations are piled on one another, almost like courses of masonry.

We may conclude, that the flux and reflux of the ocean have produced all the mountains, valleys, and other inequalities on the surface of the earth; that currents of the sea have scooped out the valleys, elevated the hills, and bestowed on them their corresponding directions; that that same waters of the ocean, by transporting and depositing earth, &c., have given rise to the parallel strata; that the waters from the heavens gradually destroy the effects of the sea, by continually diminishing the height of the mountains, filling up the valleys, and choking the mouths of rivers; and, by reducing every thing to its former level, they will, in time, restore the earth to the sea, which, by its natural operations, will again create new continents, interspersed with mountains and valleys, every way similar to those we inhabit.

We may observe in some of the abrupt grounds we meet with, sections of great masses of strata, where it is as easy to read the history of the sea, as it is to read the history of Man in the archives of any nation.

With an interest almost amounting to anxiety, geologists will watch the development of researches which may result in timing the strata and the phases of evolutionary advance; and may even-going still further back—give us reason to see in the discrepancy between denudative and radioactive methods, glimpses of past aeons, beyond that day of regeneration which at once ushered in our era of life, and, for all that went before, was 'a sleep and a forgetting'.

[Fossils found in the Secondary formation are] unrefined and imperfect [species and the species in the Tertiary formation] are very perfect and wholly similar to those that are seen in the modern sea. [Thus] as many ages have elapsed during the elevation of the Alps, as there are races of organic fossil bodies embedded within the strata.