18 T. Mellard Reade—The Eskdale Drift— 
Has the Carriage been by Land-ice ? 
Tt will be seen that the lines of travel between Carnarvonshire and 
Macclesfield diverge at an angle of 66 degrees, and between Maccles- 
field and St. Bees they sweep through as much as 180 degrees. The 
question arises if these fragments of the parent rock have travelled 
to their several localities by means of land-ice, as asserted very 
positively by the new school of glacialists, what sort of internal 
flow and movement of the ice does this involve? According to the 
well-known axiom of geology we must explain geological phenomena 
by reference to natural agencies now to be observed in action. If 
this cannot be done by exact parallel we must appeal to some well 
known principles of physics to help us out. We must show that 
the conditions differ and in what way and to what extent. 
The only knowledge we possess of the nature of the movement 
of land-ice is that in the form of glaciers in mountain districts. A 
glacier, such as it is assumed filled the Irish Sea, unless we can 
point out good grounds to the contrary, must be considered to march 
along on the same general principles as those glaciers we are 
acquainted with having steeper gradients. Any one who has seen 
a glacier, or the photograph of a glacier, will have observed that 
the material dropped upon its surface from abutting cliffs and also 
that which joins it from tributaries retains as definite and distinct 
an existence as a tramline in a main highway. This fact may be 
observed in every Alpine glacier, and it needs only a glance at the 
admirable photographs of the glaciers of the Central Himalayas 
given by Griesbach! to tell us that the same holds good in Asia. 
If, therefore, we are to consider that an ice-sheet made up of con- 
fluent glaciers acts differently and disperses throughout its mass, 
the stones taken up at one point distributing them generally and 
regularly over an immense area instead of in trains, the onus of 
proof lies on those who believe such to be possible. Personally 
I consider it to be a mechanical impossibility. Glacial ice moves 
along lines of least resistance, and these lines within certain limits, 
and under common conditions, are approximately parallel. A 
glacier from Eskdale, joining a main stream of ice from Scotland 
along the Irish Sea, would have its burden taken in train and 
deposited on a definite line, not distributed through the moving 
river of ice. We should find the probable record of its line of 
travel in the Drift itself. 
Phenomena of distribution points to Water Carriage. 
But why should we go out of our way to displace the Irish 
Sea with land-ice to provide transport for our dispersed blocks? 
The evidence that the bulk of the Drift of the plains, and much of 
the high-level Drift, is sea-bottom, whether in place or displaced, 
is so strong that no one attempts to gainsay it. Water carriage 
provides the very thing that is wanted to explain the dispersal of 
Eskdale granite boulders. Unlike the movement of ice, the sea is 
1 Mem. Geol. Survey of India, vol. xxiii. 
