At a few minutes of eleven they sighted the shore of Jamaica, five miles or so to the eastward of them.  Then John took the throttle, both engines were put into the work, and they began to whizz through the air at a clip which would have made them gasp for breath had they been in an open cockpit.  As it was, the rush of air as it swept along each side of the fuselage and off its narrowing tail, became a veritable howl in whose noise they found conversation very difficult.  Tom Meeks, who was leaning over John's shoulder and watching the instrument-board, triumphantly announced presently that they were traveling at the rate of 280 miles an hour!