Courtesy of Dr. Helen Valier, UH Honors Program
The five images below serve to illustrate the technology of incubation before the popularization of the idea by Couney and others.
The top two images are from: T. M. Rotch, Pediatrics: The Hygiene and Medical Treatment of Children. (Philadelphia: Lippencott, 1896); the bottom three are from L. E. Holt, Diseases of Infancy and Childhood. (New Your: Allpleton and Co. 1897)