We have thus very hastily traced the process of development in types and presses in the United States. Much might be said, if space permitted and the purpose of this series required it, of the invention of other presses, appliances, and methods, and of the improvements which are constantly being made in the tools and materials used in printing and the allied industries. These matters, however, are of only secondary historic interest. So much as the apprentice needs to know about them he will learn in the course of his work, as he comes in contact with them and learns their use. Perhaps the purpose of this book has been sufficiently accomplished in showing the milestones along the historical development of the two great tools of the printer, his type and his press. The list which follows is a brief statement of the most important contributions of American inventors to the art of printing: Web rotary presses. Automatic stereotyping machines. Printing machinery under electrical control. Two-revolution cylinder presses. Sheet feed rotary presses. Multicolor presses. Rotary direct and rotary offset presses for lithographic work. This, of course, includes only the inventions which are fundamental and original. Improvements of some fundamental invention, made elsewhere or earlier, are not included, although in this connection it is worth while to mention one important thing which owes to America almost everything except its original invention. This is process printing, both in black and white and in colors. Process printing was not an American invention. It is safe to say that it would be only a scientific experiment if it had not been made practical by American inventions, such as coated paper, first made for half-tone work by the Cumberland Mills Company for Mr. De Vinne, ruling machines for half-tone work, which were first made by Max Levy, of Philadelphia, about 1880, and three-color process plates, which were first made by Frederick Ives, of Philadelphia, in 1881. REVIEW QUESTIONS SUGGESTIONS TO STUDENTS AND INSTRUCTORS The following questions, based on the contents of this pamphlet, are intended to serve (1) as a guide to the study of the text, (2) as an aid to the student in putting the information contained into definite statements without actually memorizing the text, (3) as a means of securing from the student a reproduction of the information in his own words. A careful following of the questions by the reader will insure full acquaintance with every part of the text, avoiding the accidental omission of what might be of value. These primers are so condensed that nothing should be omitted. In teaching from these books it is very important that these questions and such others as may occur to the teacher should be made the basis of frequent written work, and of final examinations.