"Euler pointed out... that the rod, if of sufficient length and vertical when unstrained, may be bent by a weight attached to its upper end... [and was led] to assign the least length of a column in order that it may bend under its own or an applied weight. Lagrange followed and used his theory to determine the strongest form of column. These two... found [the] length which a column must attain to be bent by its own or an applied weight, and... that for shorter lengths it will be simply compressed, while for greater lengths it will be bent. These researches are the earliest in... elastic stability."