eleven o'clock
He had been provident enough to bring some sandwiches in his pockets -LRB- provided at the last moment by the much-enduring Walker -RRB- , and on the strength of these he laboured half the morning . It would puzzle me to explain on what scientific principle the wonderful apparatus was laid down , what mixture between the wing of a bird , the tail of a fish , and the screw of a steamer it embodied . I never was good at mechanics , and certainly Percy Rimbolt 's mechanics were such as it is given but to few to follow . Suffice it to say that by eleven o'clock the structure had reached a critical stage , and stood still for want of the cork which Appleby had been charged to procure . The day was hot , and an hour at least must elapse before the messenger could return from Overstone . Percy , therefore , improved the shining hour by a bathe in the clear stream , with whose depths he was evidently familiar . He made no attempt , pending the completion of the machine , to oppose the swift current , but diving into it from the bridge , allowed himself luxuriously to be carried down into the shallows a hundred yards below , and without even the trouble of swimming .