OPTICS - RARE CURIOSITY - "Ambigu magique ou tableaux changeans à l'usage de ceux qui n'ont pas la Berluë" (FINGERS-BOOK). In Paris, at Jacques Chereau, rue St Jacques au Grand St Rémy, 1776. Vol. in-8. 165 engraved plates coloured by hand (incomplete). Book causing an optical effect by the graduated cuts of the leaves. One makes see first white pages, then theatrical characters, soldiers, nuns... so successively without opening the book, but by leafing through it with rapidity and lowering each time the hand with lightness. The book can be turned over to see different series. Includes playing cards, women's costumes, flowers, priests, military uniforms and harlequins. VERY RARE. 15 x 11 cm. Condition B (used).