--The Master paused and fell into a deep thinking fit, as he does sometimes. He had had his own say, it is true, but he had established his character as a listener to my own perfect satisfaction, for I, too, was conscious of having preached with a certain prolixity.
--I am always troubled when I think of my very limited mathematical capacities. It seems as if every well-organized mind should be able to handle numbers and quantities through their symbols to an indefinite extent; and yet, I am puzzled by what seems to a clever boy with a turn for calculation as plain as counting his fingers. I don't think any man feels well grounded in knowledge unless he has a good basis of mathematical certainties, and knows how to deal with them and apply them to every branch of knowledge where they can come in to advantage.
Our Young Astronomer is known for his mathematical ability, and I asked him what he thought was the difficulty in the minds that are weak in that particular direction, while they may be of remarkable force in other provinces of thought, as is notoriously the case with some men of great distinction in science.
The young man smiled and wrote a few letters and symbols on a piece of paper.--Can you see through that at once?--he said.
I puzzled over it for some minutes and gave it up.
--He said, as I returned it to him, You have heard military men say that such a person had an eye for country, have n't you? One man will note all the landmarks, keep the points of compass in his head, observe how the streams run, in short, carry a map in his brain of any region that he has marched or galloped through. Another man takes no note of any of these things; always follows somebody else's lead when he can, and gets lost if he is left to himself; a mere owl in daylight. Just so some men have an eye for an equation, and would read at sight the one that you puzzled over. It is told of Sir Isaac Newton that he required no demonstration of the propositions in Euclid's Geometry, but as soon as he had read the enunciation the solution or answer was plain at once. The power may be cultivated, but I think it is to a great degree a natural gift, as is the eye for color, as is the ear for music.