The difficulties encountered in radiographing the temporal bone are due to its position at the base of the skull, to the thickness of the parts that the Roentgen rays must penetrate, and to the liability of superimposing the shadows of other portions of the skull on the skiagram of the temporal bone. By directing the rays in the anteroposterior (posteroanterior) axis of the skull Kuhne and Plagemann1, 2 have taken radiograms of the projecting portions of both mastoid processes, and have drawn clinical deductions therefrom. Voss3 and Winckler4 have obtained more detailed Roentgen pictures of the temporal bone by directing the rays in the transverse diameter of the skull.
During the past year Dr. S. Lange, radiologist to the Cincinnati Hospital, to whom I am greatly indebted, has been kind enough to undertake the radiography of the mastoid region for me. After some experimentation, at my suggestion, the radiograms