A study of the permissible speed of dehydration and oxidation of some Illinois shales
A 1916 University of Illinois engineering thesis by Fremont John August Hoehn on how fast Illinois shales can be dehydrated and oxidized without damage, written for ceramics and clay-products research. The plates are hand-drawn ink curves on printed graph paper, with handwritten captions, calibration lines for platinum-rhodium thermocouples, and heating-rate and shrinkage plots that supply grid textures, sparse line work, and period draftsman's lettering.
