Calvert was so influenced by William Blake's wood engravings that The Sheep of His Pasture is directly based on an illustration for The Pastorals of Virgil. Calvert, however, even more than Blake, exploited the ability of wood engraving to achieve the most delicate detail, so astonishing in these miniatures. Calvert's subject matter originated from a vision of the golden age of pastoral innocence and abundance that has both Christian and classical overtones. The women in The Brook resemble figures carved on antique gems, and the tree stumps symbolize the transitory nature of life.