TY  - BOOK
AU  - Usher,Abbott Payson
TI  - A history of mechanical inventions / 
U1  - 608.7 
PY  - 1959///
CY  - Boston : 
PB  - Beacon Press, 
KW  - Inventions
KW  - History
KW  - Machinery
N1  -  Includes bibliographical references
ER  -