midnight
`` Rain ! '' cried the boys eagerly . Von Hofe nodded , and the Masai struck up a `` rain chant '' which seemed to have the desired effect . By midnight the sky was overcast , and when they outspanned the next morning for the early halt gusts of wind and rain were sweeping down upon them that gradually changed to a steady , settled rain . `` This is a great piece of good luck , '' exclaimed Schoverling , revealing to von Hofe for the first time how their water supply had shrunk . `` Get out all the casks , boys , and let them fill . It 's a bad thing for the march , however . ''