three o'clock in the morning
`` He 'd go out of sight forever , '' replied Wumble solemnly . `` Some of those cuts are a thousand feet deep . '' `` What a mighty upheaval of nature there must have been here at one time , '' said Dick . By three o'clock in the morning Tom was completely fagged out and could scarcely keep his eyes open . Gradually he dragged behind the others , his eyes closing every few minutes in spite of his efforts to keep them open . `` I wish I had a cup of strong coffee to keep me awake , '' he murmured . `` How much further are you going , Jack ? ''