[Lewis Hine’s] social realism was in tune with the muckraking tenor of his times, Vicki Goldberg writes in her insightful introduction to Lewis W. Hine: Children at Work, a selection of more than 90 of Hine’s finest photographs. If their frankly prosaic character renders pronouncements about the excellence of individual pictures difficult to make, she observes, there is less question about the force and power of the totality of his work. Aesthetics were not what Hine’s work was about; it was social change that he sought. Truths were revealed in the details: the scabbed bare feet of a small girl in a cotton mill, the hugeness of a bundle of newspaper compared with the diminutive arm of the 8-year-old newsboy who clutches it. If some of the shock of these images escape us now, it is only because the camera has made us witnesses to far worse atrocities in the intervening years. But nothing takes away from the pioneering quality of Hine’s achievement.