It is the result of much pains and labor.... The book is written in plain Wen-li, and much pains has been taken to make it smooth in style and accurate in meaning. In the few equations used I have introduced the mathematical signs employed in the West, of which I have given a full explanation in the beginning of the book.... Mathematical signs and symbols are a species of universal language, used alike by all civilized nations, and it is unwise to change them until it is absolutely necessary. The young men who have given most effective assistance in the preparation of this geometry are decided in their opinion that we should not change or garble the mathematical symbolism of the West, but give it to them in its integrity. The only change made is in writing equations perpendicularly instead of horizontally,—a change which is necessitated by the form of Chinese writing. The book was published the following year. To the same committee he reports in March, 1882, that his algebra was then all in manuscript, and only needing revision and some rearrangement before printing. The geometry was followed by his algebra, first part. These have had a large sale, though, because fewer studied this branch, not the equal of the arithmetic. On January 14, 1908, he sent to the manager of the press the preface to the second volume of his algebra, which covers the same ground as the “University” edition in the United States. Of this Dr. Hayes says: “Over twenty years ago he began the preparation of Part II of his algebra, and the draft then made was used in manuscript for many years. Other duties pressed upon him, and he was compelled to lay it away unfinished. Yet he had not forgotten it, but from time to time he would make a step in advance. It was only a few months before his death that the work was completed and published.” There were a number of other books which he planned, on some of which he did considerable work, but none of which he completed. One of these was so colossal in its projected scope and scholarship that it deserves special notice because indicative of the large things to which early in his missionary career he was already eager to give his time and abilities. This was a Mandarin dictionary. In its preparation he sought to associate with himself Rev. Chauncey Goodrich, of Peking; and in writing to him under date of June 6, 1874, he thus stated his conception of the work: