His college course, notwithstanding its interruptions, was successful. President Kirkland used to say, in his quaint way, "Sparks is not only a man, but a man and a-half." He graduated with high honors. In his senior year he gained the Bowdoin prize for an essay on the physical discoveries of Sir Isaac Newton, an essay which is remembered in the traditions of the University as "a masterpiece of analytic exposition, philosophical method, lucid and exact statement." This successful essay was, perhaps, the key of his life and character, for his mind was emphatically clear, exact, analytic, mathematical; and throughout his career, the same qualities were distinct in whatever he investigated or wrote. It has, indeed, been said that his merits were already recognized by the rival University of Yale, and that offers for his removal thither had been made during one of his years at Harvard; but the friendly influence of Dr. Kirkland prevailed over those allurements, and he remained constant to his patron and college. The years 1816 and 1817 were passed by the graduate in teaching a private school at Lancaster, Massachusetts. He finished his college course at the advanced age of twenty-six, and had now added two years more to the score. At Lancaster he cultivated those habits of methodical industry which always characterized him afterwards. Soon after undertaking the school, he wrote: "I board at Major Carter's, a mile and a quarter from my school, to and from which I walk twice a day. I rose this morning an hour before sunrise, and rode five or six miles before breakfast, an exercise which I shall continue regularly. My school occupies six hours, and I have resolved to devote, and thus far, have devoted, six hours of the twenty-four to study." Before this, he has a memorandum of walking from Cambridge to Bolton, twenty-six miles; setting out at half-past one, and arriving at Bolton at eight in the evening.