he was over twenty-two years of age, when he began to fit for Harvard
College, which he entered in 1817 and graduated with high honors in
1820. He taught school in the winter months, while in college, in
Boston, Leominster, and in Canton, Mass. From 1820 to 1823 he taught a
select school in Boston.

While in college he was regarded as by far the best mathematician in his
class, and during this period thought there was the necessity for such a
book as his "First Lessons in Intellectual Arithmetic." This conviction
had been forced upon his mind by his experience in teaching. In the
autumn of 1821 he published his "first edition." His plan was well
digested, although he was accustomed to say that "the pupils who were
under his tuition made his arithmetic for him;" that the questions they
asked and the necessary answers and explanations which he gave in reply
were embodied in the book, which has had a sale unprecedented for
any book on elementary arithmetic in the world, having reached over
2,000,000 copies in this country, and the sale still continues, both in
this country and in Great Britain. It has been translated into most of
the European languages and by missionaries into many Asiatic languages.

After teaching in Boston about two and one-half years, he was chosen
superintendent of the Boston Manufacturing Company's works at Waltham,
Mass., and accepted the position; and in August, 1824, owing to the
mechanical genius he displayed in applying power to machinery, combined
with his great administrative ability, he was appointed superintendent
of the Lowell Merrimac Manufacturing Co., at Lowell, Mass. Here he
projected a system of lectures of an instructive character, presenting
commerce and useful subjects in such a way as to gain attention and
enlighten the people.