Legend to the illustrations: OPTICS:  Figs. 1—6. Phenomena of Unusual Refraction observed by Dr. Vince at Ramsgate. figs. 7—12. Diagrams Illustrative of Dr. Wollaston's Theory and Experiments on Unusual Refraction. Figs. 13, 14. Representation of the singular Phenomena of the Apparent Transference of Dover Castle to the other side of the hill between it and Ramsgate, as observed by Dr. Vince. Figs. 15, 16. Diagrams illustrating M. Biot's results respecting Unusual Refraction. Fig. 17. Phenomena of Unusual Refraction, observed in the Greenland Seas, by Captain Scoresby. Fig. 18. Shows Bouguer's method of measuring the Intensity of different Lights. Figs. 19—22. Are Illustrative of Lambert's method of measuring the quantities of Light reflected and transmitted by one or more surfaces. Fig. 23. Shows the principle of the multiplying glass,  an instrument by which an object is multiplied any number of times without being magnified. Fig. 24. Shows the principle of the common looking glass. Print  Specifics: Type of print: Copperplate engraving - original antique print Year of printing: not indicated in the print. The print came from the Edinburgh Encyclopedia published between 1808-1830 under the direction of Sir David Brewster. The last photo (not included in this offer) shows the publication schedule of individual volumes. Condition: 1 (1. Excellent - 2. Very good - 3. Good - 4. Fair). Overall Dimensions: 8 x 10.5 inches (20.5 x 26.5 cm). Paper weight: 3 (1. Thick - 2. Heavier - 3. Medium heavy - 4. Slightly heavier - 5. Thin) Reverse side: Blank Notes: 1. Green color border around the print in the photo is a contrasting background on which the print was photographed. 2. The print detail is sharper than the photo of the print.   Martin2001 Satisfaction Guaranteed Policy! Any print purchased from me may be returned for any (or no) reason for a full refund including all postage. Internet seller since 1998. Five-star service.