midnight
`` Ah , well , I 'll think it over , '' said the doctor ; and with that promise the boy had to rest satisfied . But Vane went at once to the kitchen with the intention of making some business-like measurements of the opening about the range , and to see where a boiler could best be placed . A glance within was sufficient . Martha was busy about the very spot ; and Vane turned back , making up his mind to defer his visit till midnight , when the place would be solitary , and the fire out . There was the greenhouse , though ; and , fetching a rule , he went in there , and began measuring the walls once more , to arrive at the exact length of piping required , when he became conscious of a shadow cast from the open door ; and , looking up , there stood Bruff , with a grin upon his face -- a look so provocative that Vane turned upon him fiercely . `` Well , what are you laughing at ? '' he cried .