nine o'clock
As she could not -- -LRB- to her sorrow -RRB- -- compel them to work , she would pretend not to see them , and would go in and work furiously . Rosa thought she must do likewise . Euler and Vogel would discover draughts everywhere , and fearful of catching cold , would go up to their rooms : they used to go to bed early , and would have thought themselves ruined had they changed the least of their habits . After nine o'clock only Louisa and Christophe would be left . Louisa spent the day in her room : and , In the evening , Christophe used to take pains to be with her , whenever he could , to make her take the air . If she were left alone she would never go out : the noise of the street frightened her . Children were always chasing each other with shrill cries .