Letters on natural magic, addressed to Sir Walter Scott (1832)
Brewster, David, 1781-1868 · London : John Murray · leaf 121
CONVERSION OF CAMEOS INTO INTAGLIOS. 101 window is still on our left hand, and that the light falls in the direction R L, and as every body with its shaded side farthest from the light must neces- Fig. 15. … sarily be convex or protuberant, we immediately believe that the hollow seal is now a cameo or bas-relief. The proof which the eye thus receives of the seal being raised, overcomes the evidence of its being hollow derived from our actual knowledge, and from the sense of touch. In this experiment…
Scientific recreations · Magic
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
![An illustration from Degli avanzi dell'antica Roma : opra [sic] postuma (1739)](https://img.insideoutlibrary.com/img/200/ia-degliavanzidella00over-428-49.webp)
