We believe it will be acceptable to very many by answering for them many questions which would otherwise cause much trouble and expense to decide. It will also. Save us writing numberless long letters upon the subjects here treated of. Though we are ever ready to respond without charge in regard to any matter not fully discussed in these pages, still, if any one receives this book with a passage marked which fully answers his inquiry, we trust he will feel just as well satisfied with the answer as if it was written out. The inventive talent of the West is being more and more largely employed the harvest already reaped is rich in results, but the field has only just begun to reveal its extent, and it widens out before those who are looking eagerly to it with ever more inviting prospects. The truth is, most of us are just beginning to learn how to invent, and that there are bet ter opportunities in this field to acquire rapid and honorablewealth and distinction than in almost any other. There can be no more honorable. Work than that of invention. Every step made in the saving of time and in producing new and valuable effects means a certain amount of advance in the progress of civilization. When we have so far controlled material forces as to produce twice as much in the same time as is now produced, and also do it twice as well, we shall have gained an advantage which will be apparent in added comforts to almost every home in the land. Our fathers worked more hours and harder than we for smaller material results our grandfathers received still less for their still harder toil. It is our desire to be of assist ance in every way we can in helping on this general progress.