Reports & Proceedings—Liverpool Geological Society. 139 
one circumstance or another, with the exception of that briefly stated 
by Woodward in 1910; he suggested that the boulder bed was an 
accumulation of debris dropped from sea-cliffs into deep water. No 
theory of water transport could account for the presence of a boulder 
190 x 50 X 80 feet, consisting of frequent alternations of fissile 
sandstone, etc., and there is no J evidence of glacialaction. The author 
suggested that the boulder mentioned was just a sea-stack which had 
capsized, and showed a series of photographs of the boulder bed and of 
the scenery of the present Old Red Sandstone cliffs of the Sutherland | 
coast, pointing out how the conditions of these would give rise to 
a deposit possessing exactly the characters of the boulder bed.— 
Professor Gregory congratulated Mr. Macgregor on having solved 
a problem that had baffled so many authorities. The solution showed 
that Old Red Sandstone strata must have covered that district as 
recently as late Jurassic times. 
1V.—Liverroot Gronoeicat Soctery. 
February 8, 1916.—-J. H. Milton, Esq., F.G.S., F.L.S., President, in 
the Chair. 
The following paper was read :— 
‘‘The Origin of the Trias: a restatement of the problem.” By 
H. W. Greenwood. 
The author reviewed and criticized previous theories in the ight of 
recent work, and considered them to be based largely on a mis- 
interpretation of facts, conditions having been assumed which have 
not yet been proved to have existed. The principal conclusions at 
which he had arrived were: (1) That no true line of demarcation 
existed in Great Britain between the Permian and Triassic systems, 
which must be dealt with as a whole. (2) That present-day 
topography was a partial restoration of pre-Triassic topography. 
(3) That the material of the various British Trias deposits had been 
derived from different sources, and that no general theory of river or 
desert origin was applicable to all or any of the deposits. (4) That 
the evidence pointed to arid climatic conditions existing between the 
close of the Carboniferous and beginning of the Jurassic periods. 
(5) That the Trias deposits of the Liverpool district, Cheshire, and 
the Vale of Clwyd were all derived from the same source, which lay 
to the west and south-west, and that the Bunter and Keuper divisions 
were unconformable. The high content of calcium carbonate which 
chemical analyses had revealed was:an original character, and due to 
the denudation of Carboniferous Limestone and Coa]- measures. 
V.—MInERALOGICAL Socrery. 
January 18, 1916.—W. Barlow, Esq., F.R.S., President, in the Chair. 
Professor G. Cesaro: A simple Demonstration of the Law of Miller. 
In any spherical triangle the arc x joining the apex C to a pole 
dividing the base ¢ into segments a and # is given by the equation 
cos cos ¢ = cosa sin B+ cos b sin a. Taking the apex as the pole 
