Читать книгу The Evacuation of England: The Twist in the Gulf Stream онлайн

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“But I am constrained to go one step farther in this hypothetical picture of structural defectiveness. To return to our wall of brick. It can be made up of bricks laid upon each other in consecutive tiers; it can be made up of tilted tiers of bricks, bricks laid on each other, but inclined to a horizontal plane, and finally it is conceivable that the bricks may be so arranged as to be inverted in their relations to the horizontal plane. The diagrams make clear these contrasted positions.

“Now of all these types of structures the last obviously best meets the requirements of a type which will prove the least susceptible to dislocation. I think that can be apprehended almost without explanation. A moment’s reflexion will make it conspicuous.

“The bricks tilted up in inclined tiers or beds, upon disturbance, if the cohesion between them is seriously impaired, tend to fall away from each other, and gravity increases the effects of the initial displacement. If the bricks lie flat they do not fall apart, upon the cessation of any push or upheaval, but remain disordered, falling back into some quasi-position of rest. If the bricks are inverted and form in section a series of lines converging to the base of the wall, their disarrangement is largely rectified by their own gravity, bringing them back into their first positions.