Vilad.: Map of Mecia de Viladestes, 1413. Colored reproduction of African portion as frontispiece of La R., Vol. 1. See Kret., Port., p. 126. Vivien de St. Martin: [Louis] Vivien de St. Martin, _Le nord de l’Afrique dans l’antiquité grecque et romaine: étude historique et géographique_, Paris, 1863. Wright, Lore: J. K. Wright, _The Geographical Lore of the Time of the Crusades: a Study in the History of Medieval Science and Tradition in Western Europe_, constituting _American Geographical Society Research Series No. 15_, New York, 1925. Yule, Cath.: Sir Henry Yule, _Cathay and the Way Thither_, 2nd edit., edited by Henri Cordier, 4 vols., Hakluyt Society [Publs.], Ser. 2, Vols. 33, 37, 38, 41, London, 1913-1916. Yule, Polo: See Polo. Zurla: Placido Zurla, _Il mappamondo di Fra Mauro Camaldolese_, Venice, 1806. THE REPRODUCTION OF THE LEARDO MAP By A. B. Hoen A. Hoen & Company, Baltimore, Md. [One of the first things usually asked in regard to the reproduction or facsimile of an old map is: “How was it made?” To answer this question and to give some idea of the difficult technical problems involved, Mr. Hoen, under whose direction the Society’s reproduction of the Leardo Map was made, has been kind enough to furnish the following note.—J. K. W.] The Leardo Map is painted on parchment. Some of the colors have faded, and others here and there have separated from the skin, leaving blanks in the painting. The latter defects are especially noticeable in the yellow zones encircling the map proper. To avoid the injection of the personal element into the reproduction, no attempt was made to restore the missing letters or symbols. It is further to be noted that in cases of partial legibility the very palest parts of the faded manuscript may have failed to register in the reproduction, although great care was bestowed on this part of the work. As a first step in the reproduction of the map, color separation negatives were made on photographic plates sensitized for all the colors. By interposing proper light filters and by making separate exposures for each color, negatives giving red, yellow or green, and blue or purple values were made, together with a fourth negative giving neutral tones—black and grays.