If they had been ahead of their adversaries instead of behind, they might have indulged in such sport, they thought.  But now it would be unwise to waste a moment.  They must make every endeavor to reach their next airport, Kuka, by nightfall.  This small town was on the western bank of the salty Lake Chad, in the very heart of Africa, and on the southern border of the great Sahara Desert.  It possessed no railroads or telegraph service, being linked with the outside world only by caravan route, and its inhabitants were practically all half-civilized negroes of the Fulbee tribe, who retained all of their forefathers' superstitions and wore no garb over their frescoed black bodies except a short gikki or skirt.