"Silence, sir!" thundered the old man, rising to his full height (he was exactly five-foot five) in his indignation. "I say you must use the _data_ only! You mustn't even assume _which_ it is that comes of age!" He clutched the bag as he spoke, and with tottering steps (it was about as much as he could do to carry it) he left the room. "And _you_ shall have a similar _cadeau_," the old lady whispered to her niece, "when you've calculated that percentage!" And she followed her brother. Nothing could exceed the solemnity with which the old couple had risen from the table, and yet was it--was it a _grin_ with which the father turned away from his unhappy sons? Could it be--could it be a _wink_ with which the aunt abandoned her despairing niece? And were those--were those sounds of suppressed _chuckling_ which floated into the room, just before Balbus (who had followed them out) closed the door? Surely not: and yet the butler told the cook--but no, that was merely idle gossip, and I will not repeat it. The shades of evening granted their unuttered petition, and "closed not o'er" them (for the butler brought in the lamp): the same obliging shades left them a "lonely bark" (the wail of a dog, in the back-yard, baying the moon) for "awhile": but neither "morn, alas," (nor any other epoch) seemed likely to "restore" them--to that peace of mind which had once been theirs ere ever these problems had swooped upon them, and crushed them with a load of unfathomable mystery! "It's hardly fair," muttered Hugh, "to give us such a jumble as this to work out!" "Fair?" Clara echoed, bitterly. "Well!" And to all my readers I can but repeat the last words of gentle Clara-- FARE-WELL! APPENDIX. "A knot!" said Alice. "Oh, do let me help to undo it!" ANSWERS TO KNOT I. _Problem._--"Two travellers spend from 3 o'clock till 9 in walking along a level road, up a hill, and home again: their pace on the level being 4 miles an hour, up hill 3, and down hill 6. Find distance walked: also (within half an hour) time of reaching top of hill." _Answer._--"24 miles: half-past 6." * * * * * _Solution._--A level mile takes 1/4 of an hour, up hill 1/3, down hill 1/6. Hence to go and return over the same mile, whether on the level or on the hill-side, takes 1/2 an hour. Hence in 6 hours they went 12 miles out and 12 back. If the 12 miles out had been nearly all level, they would have taken a little over 3 hours; if nearly all up hill, a little under 4. Hence 3-1/2 hours must be within 1/2 an hour of the time taken in reaching the peak; thus, as they started at 3, they got there within 1/2 an hour of 1/2 past 6. * * * * * Twenty-seven answers have come in. Of these, 9 are right, 16 partially right, and 2 wrong. The 16 give the _distance_ correctly, but they have failed to grasp the fact that the top of the hill might have been reached at _any_ moment between 6 o'clock and 7.