about midnight
`` These fellows do n't know anything about running off . I 'll tell you how to do it ; you mind your uncle ! It 's no use trying to get away from the constable , if he 's there , for he 'll catch you as quick as lightning , and he wo n't mind these fellows any more than fleas . You ought n't try to start till along about midnight , for the constable will be in bed by that time , and you wo n't have any trouble . You must have somebody to wake you up , and some of the fellows ought to be outside , to do it . You listen to your grandfather ! You ought to tie a string around your big toe , and let the string hang out of the window , the way you do Fourth of July eve ; and then just as soon as it strikes twelve , the fellows ought to tug away at the string till you come hopping to the window , and tell 'em to stop .