I can not let this little book go out without some attempt to express my indebtedness to the many friends who have aided me in its production. Some are teachers of this or other arts; some are the pupils who taught me, as I was teaching them; some are well wishers who have given friendly and helpful advice. I can not name them all here, but to some of them particular acknowledgment is due.

I am indebted to boys in the Cogswell Polytechnical College, for the drawings, and to Mr. Ernest S. Burk-hard, M. E., under whose supervision they were made.

For the frontispiece, I must thank Miss Berta Lucas, a senior in the same college, whose photograph shows her in the gown which, as the required completion of the course, she made for her graduation.

And I am under obligations to Miss Jean Parker and my sister, Mrs. Bertha Borden, for reading and revising my manuscript and proof, and also to my advisor, William H. Gorrill, Esq., Attorney-at-Law.

The pupils who have faithfully completed the course described in these pages, and from whose work nearly all the illustrations are taken, have, of course, contributed more to the volume than I can say - very likely more than I myself realize.

May 24, 1911.