indicate the significance of their achievements.

Acknowledgments are due the Editor of the Series and to members
of the staff of the Yale University Press particularly, Miss
Constance Lindsay Skinner, Mr. Arthur Edwin Krows, and Miss
Frances Hart--without whose intelligent assistance the book could
not have been completed in time to take its place in the Series.

H. T.

COLLEGE OF THE CITY OF NEW YORK,
May 10, 1921.

CONTENTS

I. BENJAMIN FRANKLIN AND HIS TIMES

II. ELI WHITNEY AND THE COTTON GIN

III. STEAM IN CAPTIVITY

IV. SPINDLE, LOOM, AND NEEDLE IN NEW ENGLAND

V. THE AGRICULTURAL REVOLUTION

VI. AGENTS OF COMMUNICATION

VII. THE STORY OF RUBBER

VIII. PIONEERS OF THE MACHINE SHOP