Robert Rosenblum, "Cubism and Twentieth-Century Art":
"Boccioni's Elasticity of 1912 now begins to focus more exclusively on a study of vigorous, sequential movement, as foreign to the intellectual dynamics of Analytical Cubism as the aggressively harsh and sour colors. A literal demonstration of horsepower, Boccioni's machinelike horse, with its virile, black-booted rider, thunders across an appropriately mechanized landscape of high-tension poles and factory chimneys. If the splintered planes of such a work depend on the Cubist analysis of solid and void, the reasons for this dismemberment are very different. Here mass has been shattered by the dynamic energies of horse and rider, with their up-and-down as well as forward motion, rather than by the quiet spatial investigations of Cubism. If in Cubism the spectator, by implication, moves around static objects, in a Futurist canvas like this the spectator remains static while moving objects rush across his field of vision. Again, vestiges of an Impressionist viewpoint may be sensed here, especially in the way the extremities of horse and rider lie beyond the picture's edge. By using this Impressionist compositional technique, Boccioni implies not only that his tightly compressed subject is so dynamic that it must burst its four-sided confines, but that it is a fragment of a constantly changing visual experience."