In the pursuit of his plan he sought the aid of competent scholars in the north and in central China, so as to learn the colloquialisms and the usage of words; also in the preparation of a syllabary of the sounds of characters as heard in each of the large centers where foreigners are resident. To accomplish this he also traveled widely. Late in 1889, after a summer spent in studying the dialects of China, he, in company with Julia, made a three months’ trip to the region of the Yangtse, going down on the Grand Canal, spending a month on the great river, and remaining a month at Nanking; always with the main purpose of informing himself as to the current Mandarin, so as to perfect his book. This tour enabled him to give it the final revision; and in his opinion it “more than doubled the value” of the “Lessons.” As finished, they were a huge quarto of six hundred pages, which with the help of Mrs. Julia Mateer he saw through the press down at Shanghai. In 1901, assisted by Mrs. Ada Mateer, he issued a more elementary work of the same general nature. The protracted study and care which he put upon the “Lessons” were characteristic of him in all his literary productions. Upon this subject no one is better qualified to bear testimony than is Dr. George F. Fitch, Superintendent of the Presbyterian Mission Press, at Shanghai, who speaks from direct personal observation. He says: One very marked characteristic of Dr. Mateer was the almost extreme painstaking with which he went over any work which he was getting ready for publication; revising and re-revising, seeking the judgment of others, and then waiting to see if possibly new light might dawn upon the subject. I remember reading shortly after I came to China the manuscript of a paper which he had prepared with great labor, upon the much-mooted “term question”; and in which he had collected, with infinite pains, seemingly a great number of quotations from the Chinese classics and other native works, bearing on the use of Shen as the proper word for God in Chinese. I urged him to publish at once, as I thought it might be useful in helping settle that question. But he stoutly refused, saying that it was not yet complete. Nor did it finally see the light, in print, until nearly twenty years afterward. None of his books at all reveal the protracted and toilsome process of the preparation. We see only the result of years of research. For instance, in his library there was a long row of Chinese books each one of which showed a large number of little white slips at the top. Each one of this multitude of marks had been placed there by some student whom he had employed respectively to read works in Chinese likely to use the word Shen, in order to indicate the passages at which he needed to look. All these were canvassed, and the different shades of meaning were classified.