And so, on to the aviation field near the magnificent ruins of ancient Lebna. The extent of these ruins, great arches, portals and columns of marble, porphyry and cut stone overlooking the sea, though half buried by sand dunes, presents conclusive evidence of a former populous and magnificent city. In the morning, when they expected to return to Tripoli, a heavy fog drifting from the southwest rested over the sea, and though conditions were not ideal, they started home. The fog, far below, covering the sea as far as vision reached, looked like an immense broken billowy ice field, or millions of big powder puffs jammed together in an immense plain. Following the distinguishable shore line they came within fifteen miles of Tripoli where the fog, with dangerous perverseness, extended far into the desert. Earth passed out of sight and they were in a private world of much space and no substance, as might have been before land and sea were formed. Far below on the cloud-like surface of the fog a circular rainbow preceded them and when the operators, thinking the camp near, descending, drew near the fog, in the white center of the rainbow-circle, ghost-like, appeared a perfect silhouette of their airplane. Then through the fog, as cold as a winter mist, they came in sight of earth; much too close for comfort, where a little dip or swerve might land them in the palm tops, and the edge of the landing field a quarter of a mile to the right, then up into the fog again and to a safe landing. On a day in July, they started for Zuara at six o'clock in the morning; and the higher up they went the hotter it grew. The operators, returning to camp, refused to make the trip as the thermometer registered 60 centigrade at five hundred meters, stating a ghibli was raging at a higher altitude. Five hours later Tripoli and the whole desert country south, suddenly and without warning, became a blast furnace of heat and a place of dust and torture. Those familiar with the hot winds which at times devastate the crops and make life miserable southwest of the one hundredth meridian in Oklahoma and Texas would consider them the cool breeze of a summer twilight in comparison with the ghibli or Sahara sandstorm. Some writer tells that "a geologist has estimated that a single windstorm across the Sahara once carried nearly 2,000,000 tons of dust from Africa and deposited it over Italy, Austria, France and Germany." At the end of four months spent in Tripolitania, John Cornwall's contract for a year's service with the Y expired and he asked for transportation to America. He made the trip across the sea from Tripoli to Syracuse, from Syracuse to Bologna by rail except across the strait of Messina, and then in a day or so to Genoa, where he took passage on the Giuseppe Verdi for America.