SHEET METAL DRAFTING
Mc Graw Hill Book Co. Inc.
PUBLISHERS OF BOOKS FOR
Coal Age • Electric Railway Journal
Electrical World• Engineering News-Record
American Machinist • Ingeniería Internacional
Engineering & Mining Journal • Power
Chemical & Metallurgical Engineering
Electrical Merchandising
INDUSTRIAL EDUCATION SERIES
SHEET METAL DRAFTING
PREPARED IN THE
EXTENSION DIVISION OF
THE UNIVERSITY OF WISCONSIN
BY
ELLSWORTH M. LONGFIELD
HEAD, SHEET METAL DEPARTMENT,
BOSTON TRADE SCHOOL
First Edition
McGRAW-HILL BOOK COMPANY, Inc.
NEW YORK: 370 SEVENTH AVENUE
LONDON: 6 & 8 BOUVERIE ST., E. C. 4
1921
Copyright 1921, by the
McGraw-Hill Book Company, Inc.