Just as we had started to nose downward, the starboard motor began to pop ominously, as if it were backfiring through one of its carburetors. Alcock throttled back while keeping the machine on a slow glide. The popping thereupon ceased.
By eight o'clock we had descended from eleven thousand to one thousand feet, where the machine was still surrounded by cloudy vapor. Here, however, the atmosphere was much warmer, and the ailerons were again operating.
Alcock was feeling his way down gently and alertly, not knowing whether the cloud extended to the ocean, nor at what moment the machine's undercarriage might touch the waves. He had loosened his safety belt, and was ready to abandon ship if we hit the water. I myself felt uncomfortable about the danger of sudden immersion, for it was very possible that a change in barometric conditions could have made the aneroid show a false reading.
A SPECIAL KIND OF GASOLINE HAD TO BE USED
ALL ABOARD FOR THE FIRST TRIAL FLIGHT
But once again we were lucky. At a height of five hundred feet the Vickers-Vimy emerged from the pall of cloud, and we saw the ocean—a restless surface of dull gray. Alcock at once opened up the throttles, and both motors responded. Evidently a short rest had been all that the starboard motor needed when it began to pop, for it now gave no further signs of trouble.
I reached for the Drift Bearing Plate, and after observation on the ocean, found that we were moving on a course seventy-five degrees true, at one hundred and ten knots ground speed with a wind of thirty knots from the direction of two hundred and fifteen degrees true. I had been reckoning on a course of seventy-seven degrees true, with calculations based on our midnight position; so that evidently we were north of the prescribed track. Still, we were not so far north as to miss Ireland, which fact was all that mattered to any extent.
In my correction of the compass bearing, I could only guess at the time when the wind had veered from its earlier direction. I made the assumption that the northerly drift had existed ever since my sighting on the Pole Star and Vega during the night, and I reckoned that our position at eight o'clock would consequently be about fifty-four degrees N. latitude, ten degrees thirty min. W. longitude. Taking these figures, and with the help of the navigation machine, which rested on my knees, I calculated that our course to Galway was about one hundred and twenty-five degrees true. Allowing for variation and wind I therefore set a compass course of one hundred and seventy degrees, and indicated to the pilot the necessary change in direction by means of the following note and diagram: