52 
But seeing that action of physical agencies other than the 
very trivial operation of "those of which we have ex- 
perience," are denied by Mr. lirough Smyth, or "that 
nature worked at times convulsively," — notwithstanding 
the evidences there are of revolutions of ocean surface, 
yielding a vast denuding, disintegrating, and drifting force ; 
and an unintelligent and prejudiced mode of reasoning, 
induces disregard of the labours of the student of physics to 
discover and disclose the primary cause evoking epochal 
displays of such force, the present depression fallen upon 
mining enterprise, and reduction of the number of working 
miners now in Victoria, alluded to in the Argus summary 
quoted from, is only what we have had reason to expect. 
In his Progress Report Mr. Brough Smyth, in advising as 
to a locality near Coleraine suitable for a search for coal, 
remarks, " We are guided more by the lithologieal character 
of the rocks than by the dips yielding conclusions respecting 
the structure of this part of the trough." This is an instance 
of the difference of our opinions as to the several conditions 
under which coal is produced, anil the circumstances which 
should guide US in the search for it. I hold, on physical 
principles, that the dip is the main point. The deposit of 
vegetable matter transformed into coal, if there be any local 
deposit thereof, will be in the bed or deepest hollow of the 
original trough, or depressed surface. This, at every suc- 
ceeding epoch of oceanic submergence, would be more or 
less tilled up with sedimentary deposits, including, possibly, 
layers of vegetable accumulations, drifted and precipitated 
from the superincumbent ocean, as filled with mechanically 
suspended debris of the lands over which the tunmltuous 
waves of an ocean, broke loose from its barriers, had swept. 
So long as a depression remained, so long would there lie 
deposit therein, whether of earths, sand, or vegetable 
matter — the latter, now lignite, or coal, according to age. 
But where the surrounding structure of the rocks indicates 
a depression, similar at a former epoch to the characteristics 
of an amphitheatre, or lake, the finding surface, or shallow, 
indications of a seam of lignite, or coal, would appear to me 
prima fach; evidence of thicker deposits, to be searched for 
beneath by boring. In the Atlantic Ocean, some 1,200 
miles west of the Irish coast, there is said to be 
an abrupt depression of the ocean bed to the depth 
of some 7,000 feet. If the present ocean presents, 
as is probable, as varied an aspect of bottom surfaco 
as our mountains, valleys, and plains do superficiary, 
there must still be depressions of many hundred feet deep 
