six o'clock
`` Thanks , I 'll be on my guard , '' answered Tom , with a shiver . `` I 've had all I want of icy baths this winter . '' The girls were sorry to see the boys leave so quickly , but were consoled when Tom promised to stay longer on the return . On the following morning breakfast was had at six o'clock , and by seven they were off , everybody wishing them a good time . Only Mrs. Barrow knew that the boys were on a treasure , and not a bird and wild animal , hunt . It was a clear , frosty day and everybody was in the best of spirits . The boys wore fur caps and warm clothing , and each was provided with either a rifle or a shot-gun .