Santarem, Vol. 3, p. 399, and Berchet, op. cit., p. 6, cite two mid-eighteenth century MSS in the Library of St. Mark’s, Venice, which contain entries relating to a map by Giovanni Leardo dated 1447. One of these MS is that of the Doge Marco Foscarini (Codex ital., XI, 123, p. 42), the other that of a contemporary scholar, Giovanni degli Agostini (Codex ital., VII, 291, p. 542; this and the preceding reference were furnished to the present writer by the Chief Librarian of the Library of St. Mark’s; they do not agree exactly with the references as given by Santarem and Berchet). The passage from the Foscarini MS (Fig. 2) may be translated thus: “Gio. Leardo, who flourished in 1440, made a planisphere on parchment on which was written Leardius de Venetiis me fecit anno 1447. It was at the house of (era presso) Bernardo Trevisano. Apostolo Zeno saw it many times and marveled at seeing the exactness of the design.” The passage from the Agostini MS (Fig. 3) runs as follows: “Giovanni Leardo: This (man) lived shortly before the middle of the fifteenth century, and he delighted in geography and spheres. In the Trevisan Library was preserved a planisphere by him on parchment on which could be seen delineated the whole terraqueous globe with all the signs and celestial constellations, beneath which, according to his assertion, every part is placed. At the bottom of this parchment these words may be read: Joannes Leardius de Venetiis me fecit ab anno 1447. It is curious to see how in his time, when not many discoveries had been made and navigation was so little advanced, the positions of the provinces and of the seas were conceived.” Berchet, op. cit., p. 7, points out that the arms at the top of the parchment of the Leardo map now belonging to the American Geographical Society are those of the Trevisan house. He reads incorrectly, however, the date given by Agostini as 1452, concluding therefrom that the map mentioned by the latter was the same as the Society’s map, the date of which he also reads as 1452. In view of the actual difference in the dates, we may conclude that Leardo constructed two maps for the Trevisan family, and that the one dated 1447 is yet to be rediscovered. Figs. 2 and 3—Passages from mid-eighteenth century manuscripts in the Library of St. Mark’s, Venice, in which reference is made to a map by Giovanni Leardo, dated 1447. See note 4. Fig. 2—from manuscript of the Doge Marco Foscarini. Fig. 3—from manuscript of Giovanni Agostini. [5]Although the Society’s map is not, perhaps, one of the great, outstanding monuments of medieval cartography, the assertion of Theobald Fischer (Sammlung mittelalterlicher Welt- und Seekarten, Venice, 1886, p. 104) that the Leardo maps of 1448 and 1452 were “von geringem Wert,” seems too harsh. [6]There follows a transcription of this legend. Missing passages supplied from the Vicenza map as transcribed on Santarem’s reproduction are given in square brackets: ... chreatore de Tute le Cose chreate et non chreato et E En 3 persone et una medexima sustanzia et uno Idio El quale En .i.inita (divinita?) E Incomprensibelle aiomeni et aianzelli quanti uisono dal zentro per sino Ala zirconferenzia En umanita ... " ... ene Maria et farsi homo pasibelle et sostener morte per Redimer Lumana zenerazione et resusito Il Terzo zorno et asexe ... (en?) ziello ala destera del padre et al nouisimo di zudigera zusti et pechatori. Al nome de quel dio che cosi veramente chre ... at" ... como La Tera et le Ixole stano nel mare et Molte prouinzie et monti et fiumi prenzipalli sono nela Tera El diamitro dela Tera sie meglia 6857 secondo Macobrio ezelentisimo Astrologo et geumetrico. El diamitro de Laqua" [sie meia 14796. El diametro de laiere sie m]eglia 31929¹/7. E diamitro del fuoguo 68191²/7. El diamitro de La Luna sie meglia 147149. El diamitro de mercurio sie meia 20(?)7533. El diamitro de venus sie meglia 692703. El diamitro del solle sie meia 1494781. El diamitro de mar(te) "... eia 6532374¹/7 (Jupiter). El diamitro de saturno sie Meia 139979424/7. diamitrus horbis signiorum sie meia 29995591. diamitrus horbis aplanes sie meia 642762665/7. diamitrus horbis christalini sie meia 137724(?)856. pitagora dize che da La ".... [El primo zircholo che zirconscrisse Il sopra schri]to mapamondo sie de la raxon de la pasqua de la Rexurezione per Ani 95. Comenza nel 1453 adi primo aprille conpie nel 1547 adi 10 Aprille. quando si Troua nele caxelle Letera M aueremo La pasqua de marzo, quando si Trouera Letera A Aueremo" [quando la viene daprille. quando si troua letera B que]lano aueremo Bixestro. El segondo zircolo sie de I12 mexi dellano et quando Il sole Entra En cadauno dei 12 segni zelesti. El Terzo zircollo sie de 19 Letere de lalfabeto per Atrouar la raxon de La Luna. El quarto zircollo sie dei numeri (?)" [di zorni de mexi. El quinto sie de le ore.] El sesto zircollo sie Iponti de le hore. El setimo zircollo sie Le Letere dominicale. Lotauo zircollo sie Le ore de La grandeza del di En tututo (sic!) El tenpo de lano (?). El nono zircolo sie dei menudi che auanza oltra Le ore ne la grandeza del di. El dezim "... uoler sapere quando rinoua La Luna de Zugnio del 1453. nel dito mileximo Abiamo per letera concorente Letera C. Auoler atrouar La conioncion de la Luna dobiamo Atrouar Letera C nel mexe de zugnio E alincotro se trouera di.. "... (rin) ouera La Luna de cadauno mexe del dito mileximo. El mileximo comenz(a) de Zenaro nel 1454 aueremo concorente Letera d ecosi se schore ogniano 1 Letera de lalfabeto. Et quando sizunze aletera T l’Altro ano drieto sitorna Aletera A. "... raxone comenza Ala Leuar del solle e intendese atanti di et Atante hore et atanti (?) ponti. ponti 1080 sintende 1 hora. Ale fiade En uno mexe si troua 2 fiade una Letera en quel mexe La luna rinoua 2 fiade etc. [7]By the “diameters” of the sun, moon, and planets Leardo obviously means the diameters of the orbits. Macrobius, Commentaria in somnium Scipionis, I, 20: 20, gives the diameter of the earth as 80,000 stades, which might, if converted into Arabic miles, be approximately the 6857 miles of Leardo. According to Macrobius the radius of the sun’s orbit is 4,800,000 stades (ibid., I, 20: 21); the diameter of the sun’s orbit would therefore be 9,600,000 stades, or 120 times that of the earth. The diameter of the sun’s orbit according to Leardo is 218 times that of the earth. On the authority of Porphyry, Macrobius (ibid., II, 3: 14) gives the relative distances between the planets; but Leardo’s figures bear no relation to these. I have not been able as yet to trace the origin of Leardo’s figures. [8]H. Grotefend, Zeitrechnung des deutschen Mittelalters und der Neuzeit, Vol. 1, Hannover, 1891, p. 203 (reference kindly suggested by Dom Hugh G. BÉvenot of Weingarten Abbey, WÜrttemberg, Germany). [9]Grotefend, op. cit., p. 113, asserts that O was usually omitted to avoid confusion with zero. Leardo, however, includes O. J and I are counted as one letter. The golden number of 1453 is 10; Leardo’s A corresponds with golden number 8. [10]The following is a comparison of the times of the new moon on certain dates as indicated by Leardo with the actual times as determined for the meridian of Venice from Th. von Oppolzer, Canon der Finsternisse (constituting Denkschr. Kaiserl. Akad. der Wiss. in Wien, Math.-naturw. Classe, Vol. 52, 1887). | Leardo’s Times | Actual Times | | 1453 | Dec. 1 | ? hrs. | 203? pts. | Nov. 30 | 2.40 P. M. | | 1455 | Apr. 16 | 21 hrs. | ? | Apr. 17 | 12.22 A. M. | | 1456 | Apr. 6 | 7 hrs. | 229 pts. | Apr. 5 | 4.25 A. M. | | 1461 | Jan. 11 | 21 hrs. | ? | Jan. 11 | 8.44 P. M. | | 1468 | Feb. 23 | 14 hrs. | 747 pts. | Feb. 23 | 10.15 P. M. | The discrepancies are too great and too variable to enable us to come to any very definite conclusions as to the place or manner of origin of Leardo’s figures. [11]The division of the hour into 1080 points (3×6×60, as Dom BÉvenot points out) is puzzling. More usually the hour was subdivided into four points. See Grotefend, op. cit., p. 188. [12]The dominical letter for 1453 was G. [13]On the basis of certain of the figures given by Leardo for the lengths of the days at about the times of the solstices, I have estimated that this table was worked out for about lat. 42° 45' N, which is more nearly the latitude of Orvieto than that of Venice (45° 30'). (This calculation was made with the Smithsonian Meteorological Tables, 4th edit. (constituting Smithsonian Misc. Colls., Vol. 69, No. 1), Washington, 1918: Table 87, “Duration of Sunshine at Different Latitudes,” and Table 88, “Declination of the Sun for the Year 1899.” The difference in the declination of the sun for 1452 and 1899 is negligible.) Dom BÉvenot writes: “I fancy day lengths were reckoned roughly for degrees. Here in Weingarten about 1490 they used tables drawn up for lat. 45° N, though the place is actually 47° 40'.” [14]I am indebted to Dom BÉvenot for the following comment: “Concerning the calendar of saints I find the good Venetian has inserted besides the usual feast of St. Mark, patron of Venice, on April 25 two more: that of his apparition and the finding of his relics on June 25 and a third feast on Jan. 31 (translation). The last two were special for the diocese of Venice (Aquileia). The calendar for Aquileia is given at the beginning of Grotefend, op. cit., Vol. 1, but does not quite tally with Leardo’s list of saints. Perhaps this is because Grotefend has modernized the calendar. It may be that Leardo, living perhaps elsewhere than in Venice or its diocese, put in feasts that were dear to him. Indeed, in view of your findings for latitude from the length of the days [see preceding note], Rome is the most likely place, perhaps, for the Venetian embassy. It lies nearly in lat. 42° N; if we allow for Leardo measuring the length of the days according to the apparent sunset and sunrise, this may well explain a discrepancy of the greater part of a degree.” [15]Berchet, op. cit., p. 7. [16]See H. F. Lutz, Geographical Studies Among Babylonians and Egyptians, in Amer. Anthropologist, Vol. 26 (N.S.), 1924, pp. 160-174. [17]See Appendix, Nos. 305, 619. [18]Kretschmer, CE see p. 63. [19]Particularly the famous Catalan Atlas of 1375 see p. 63. [20]For the names of and for bibliographical references relating to some of these maps see the list of references on pp. 63-67, sub CD, Mauro, Piz., Vat., Vilad. [21]This Latin translation of Ptolemy’s Geography was begun by the Byzantine scholar Emmanuel Chrysoloras and completed by Jacopus Angelus in 1410; manuscripts of this translation were accompanied by maps, which, however, differ from the well-known maps in the Ptolemaic atlases of the late fifteenth and sixteenth centuries. The latter were the work of Dominus Nicolaus Germanus, known as Nicholas Donis. See A. E. NordenskiÖld, Facsimile Atlas to the Early History of Cartography, transl. by J. A. EkelÖf and Clements R. Markham, Stockholm, 1889, pp. 9-10. [22]Like the Leardo map of 1452, the map of Walsperger, 1448, reveals Ptolemaic influence in some of its names although all the topographical features are strictly medieval. The Genoese world map of 1447 in its elliptical form is the result of a more serious attempt to reconcile the Ptolemaic geography with the traditional views. See Kretschmer, CE, pp. 76-77; on the Walsperger map, Kretschmer, Eine neue mittelalterliche Weltkarte der vatikanischen Bibliothek, in Zeitschr. Gesell. fÜr Erdkunde zu Berlin, Vol. 26, 1891, pp. 371-406, reference on pp. 376-377. On the Genoese world map see the extended commentary of Fischer, op. cit., pp. 155-206. [23]Kret., CE pp. 82-83. [24]See Kret., Port., pp. 81-93; see also E. L. Stevenson, Portolan Charts: Their Origin and Characteristics, with a Descriptive List of those Belonging to the Hispanic Society of America, New York, 1911, p. 19, where it is suggested that the faulty orientation of the Mediterranean may be in part connected with the persistence since the time of Ptolemy of the practice of placing Constantinople on maps “too far to the north by at least two degrees.”
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