Read it through once

For days he made ceaseless calculations, but they were all wondrously unsatisfactory. He found that he could establish nothing. He finally concluded that the only way to prove himself was to go into the blaze, and then figuratively to watch his legs to discover their merits and faults. He reluctantly admitted that he could not sit still and with a mental slate and pencil derive an answer. To gain it, he must have blaze, blood, and danger, even as a chemist requires this, that, and the other. So he fretted for an opportunity.