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1907 G. Bacon Record of Aeronaut xiv. 261 Bacon leant far out looking at the cloud floor.

1938 C. Day Lewis Overtures to Death 15 Crawling in echelon, Beneath the cloud-floor, the bombers come.

1940 Illustr. London News 197 4 The ‘holes’ in the cloud-floor provide the enemy pilot with frequent glimpses of the ground.