about three o’clock
As they approached they could see the masses of vapor more plainly , and it appeared that some great commotion must be going on inside the big hole , since clouds of steam arose . `` I only hope it does n't prove too hot for us , '' observed the professor . `` However , I provided a water jacket for the ship , and we may need it , as well as the vacuum chambers to keep the heat from us . '' It was about three o'clock when the flying ship reached the edge of the island . From there it was about a mile to the rim of the big hole , over one side of which the waters of the ocean poured with a roar that could be heard over half a mile off . `` I think we had better halt and see that everything is in good shape before proceeding , '' said Mr. Henderson . `` Jack , you and Mark make a thorough inspection of the engine room , and see that all the apparatus is in working order . ''