The paper used in the book is thick, the type large. Words and phrases to which the author desires to call special attention are printed in italic characters, and as more than half the book is, in the author's eyes, important, more than half the book is printed in italics. In 1788, when Nicholas Pike published his arithmetic, Greenwood's book was entirely unknown, and Pike's was believed to be the first arith metic written and printed in America. The first arithmetic which enjoyed general popularity and reached an extended circulation in the colonies was the School-master's Assistant, by Thomas Dilworth. The first edition of this was published in London in 1744 or '45. According to Wickersham, there appeared a reprint of this in Philadelphia in 1769. Other American editions were brought out at Hartford in 1786, New York in 1793 and 1806, Brooklyn in 1807.