An allusion is a reference to a well known person, place, event, literary work, or work of art. There are three important allusions in Ray Bradbury's short story "There Will Come Soft Rains." First, Bradbury alludes to the atomic bomb blast at Hiroshima in 1945 when he reveals that the images of four people and a ball have been imprinted in charcoal on one wall of the automated house:
The entire west face of the house was black, save for five places. Here the silhouette in paint of a man mowing a lawn. Here, as in a photograph, a woman bent to pick flowers. Still farther over, their images burned on wood in one titanic instant, a small boy, hands flung into the air; higher up, the image of a thrown ball, and opposite him a girl, hands raised to catch a ball which never came down.
Photographs of these types of images were taken in the aftermath of the attack on Hiroshima. Bradbury also alludes to Hiroshima by making the date August 5, 2026. The date of the original bombing of Japan was August 6, 1945. By making the date the fifth, Bradbury may be suggesting that more attacks are on the way, just as a second bomb was dropped on Nagasaki three days later in 1945.
A second allusion is to the poem of the same name which is significant because Sara Teasdale's "There Will Come Soft Rains" envisions a world devoid of human beings. In her poem, however, the animals, trees and birds are still alive, never noticing the absence of humans. Teasdale even suggests they may be better off without mankind. Likewise, the automated house never seems to notice that there is no human presence as it goes on with its daily routine.
Finally, Bradbury mentions the modernist artists Pablo Picasso and Henri Matisse. Their paintings are consumed in the fire which destroys the house. The artistic visions of Picasso and Matisse are considered harbingers of the modern world, the world which would ultimately create the technology that is used in the house and which is responsible for the invention of atomic weapons. One might wonder if one of the paintings was Picasso's famous interpretation of an air raid on the Spanish city of Guernica during the Spanish Civil War. The painting depicts a frightening scene with distorted and twisted bodies, some looking with horror at the sky above.