 | Sir Norman Lockyer - 1877 - 634 pages
...difference of texture, due generally to some included organism, had determined and limited the areas over which infiltration had produced bands of colour....then drew attention to a series of specimens which showed that when flint or other material of a similar texture was struck by any object such as a round-headed... | |
 | Cambridge Philosophical Society - 1880 - 494 pages
...Specimens illustrating the Formation, Weathering, and Fracture of Flint: with Note by Professor STUART. PROFESSOR HUGHES exhibited three series of specimens...other material of a similar texture was struck by any ohject such as a round-headed hammer, so that the blow was symmetrically distributed over a small area,... | |
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... flints he exhibited and distinguished two kinds — one in which infiltration had taken place all round the outside, often a good test of the drift origin of certain fragments ; and the other in which a difference of texture, due generally to some... 