Soon the queer actions of the stranger were quite forgotten in the deep interest of the three young men in their work.  With the prospect of a world tour before them if the Sky-Bird turned out well, they now had more incentive than at the beginning to build the machine with the utmost skill and attention to every detail.  Some changes, calculated to make the craft better adapted to the peculiar conditions she would be likely to meet in such a varied temperature were put into effect, but on the whole they found their original plans so well laid that no important features seemed to require modification or abandonment.