DURHAM AND NORTHUMBERLAND. 63

rolling about, from the equator to the polesand from the poles to the equator, we shallbe less astonished at the idea of long periodsof time producing wonderful and sublimechanges in the appearance of our planet, andin the nature and form of its rocks and stra-tifications.

The theory of Dr. Hutton is further corro-borated by the alluvial formations in manyparts being of different constituent materials;some spaces of them being, hard, calcareous,and rounded, while other parts are in theirnative roughness; others are partly deprivedof their angular edges, and become in somemeasure rounded, though partially as ifbrought from graduating distances, inferior tothe distance from whence the rounded pebbleshad been brought.

Besides these theories we have those of Ber-trand, Humboldt, Werner, Saussure, Cuvier,and Bakewell, and lately some very interestingpapers have appeared in Thomson’s Annals,written by Mr. J. B. Longmire, on formationsand their different phenomena. Mr. Longmirehas classified the primitive formations undernew names, according to their being stratifiedor not; calling those formations which are not