Caias College, Cambridge. This work details the history of the Calculus of Variations from its origin until the close of the eighteenth century, and has obtained a high reputation for accuracy and clearness. During the present century some of the most eminent mathematicians have endeavoured to enlarge the boundaries of the subject, and it seemed probable that a survey of What had been accomplished would not be destitute of interest and value. Accord ingly the present work has been undertaken, and a short account will now be given of its plan.