Note 8 — Chapter XVII

Journal of Geograph. Soc., vol. v., p. 12. Mr. Lyell (vol. iv., p. 360) has compared the fissures, by which the columnar structure seems to be determined, to the joints that traverse nearly all rocks, but which are best seen in the non-stratified masses. I may observe, in the case of the frozen snow, the columnar structure must be owing to a “metamorphic” action and not to a process during deposition.