TONOGRAPHY is a new term for a procedure which consists essentially of the observation of the drop in ocular tension that occurs during prolonged or sustained corneal application of a tonometer of the Schiøtz type. Fundamentally, this drop in ocular tension is an example of the reaction of the normal human eye to localized pressure from without, causing deformation, indentation, and distention of the eyeball wall. At present tonography may be described as a promising approach to a number of ophthalmological problems, the unexplored ground vastly exceeding the explored territory. HISTORY OF TONOGRAPHY While the phenomenon of a drop in ocular tension under the influence of repeated or prolonged application of the tonometer was known to Schiøtz and his early followers, its first systematic study appears to have been made and reported by Wegner.1 When a Schiøtz tonometer with the 5.5 gm. load was allowed to rest on the