William Turner, Lecture Diagrams. Prepared for his lectures as Professor of Perspective at the Royal Academy. For example Diagram 73: Perspective Construction of an Ionic Capital. Diagram 65 and 66: views of a prison interior based on an etching from Piranesi’s Prima Parte de Architettura e Prospettiva.
Lecture Diagram 21: Representation of a Globe in Perspective (after Thomas Malton Senior), 1810. Turner is adapting a passage from the elder Thomas Malton for his own teaching.