"As regards strategical reconnaissance," it says, "a General is probably now justified in requiring a well-trained flyer, flying a modern aeroplane, to reconnoitre some 70 miles out and return 70 miles. This would be done at a speed of, say, 60 miles an hour in ordinary weather over ordinary country. Thus within four hours, allowing a wide margin, a report as to the approximate strength, formation and direction of movement of the enemy, if he is within a 70-mile radius, should be in the hands of the Commander."
