Changes made:
Some missing punctuation has been added silently, some minor typographical errors have been corrected silently.
Some tables, calculations, formulas, etc. have been re-arranged for better readability.
Some of the illustrations and their captions have been rotated.
Page 15: apply a straight-edge F changed to apply a straight-edge D
Page 75, Fig. 75: Lehman’s Scale changed to Lehmann’s Scale
Page 83: the third reference line C D changed to the third reference line C A
Page 132: the erect manner and the reverse manner changed to the erect manner and the reverse manner.
Heading PLATES added after Index.