six o'clock
The Rover boys had already arranged about the boats , and promptly on time they set off down the river in the direction of the lake . They had to row past the several docks of the town , and then drew up at a small wharf , leading up to the Clearwater Hall grounds . When the girls appeared , they were accompanied by one of the teachers , who had been sent down , evidently , for the purpose of looking the cadets over . `` Now remember , do not stay out any later than six o'clock , '' said the teacher , as the girls were entering the two rowboats , assisted by the boys . `` Oh , we 'll have to come back a little before that time , '' answered Jack . `` You see , we are due at Colby Hall at that hour . '' `` Very well then , '' said the teacher .