six o'clock
The full moon , as seen from the earth , appears just about half a degree in diameter -- sometimes a little more , sometimes rather less ; so the earth was apparently about thirty times the diameter the moon usually appears to us . It was only a thin crescent where lighted by the sun , but well might M'Allister describe it as `` enormous , '' for it appeared still larger to him when he saw it some thirty minutes earlier and mistook it for the new moon . When we came down again John , very thoughtfully , said to me , `` Professor , you have had a very long , tiring day ; and when we reach the moon , we shall probably stay up several hours to look at it , so you had better take as long a sleep as possible . There will be no need to break your rest , for I 'm the younger , and will get about by six o'clock , and relieve M'Allister , who can go on all right up to then , as he has three hours less work to his credit than we have to-day . If your advice is needed , I will call you at once ; but , no doubt , we shall do very well till we arrive within a few thousand miles of the moon . We will slacken speed very gradually from about two o'clock in the afternoon , so as not to approach the orb too rapidly . '' I had , indeed , as he said , had a long , tiring day , having risen soon after four o'clock yesterday morning , and it was now nearly 2 `` A.M. '' by terrestrial time ; so , thanking him for his kind consideration , I bade them both `` good night , '' and gladly proceeded to bed , John following soon after .