Explanation
The following commentary is divided into sections numbered with Roman numerals corresponding to the Roman numerals on the general key map ([Fig. 4], at end of book). Each item is given an Arabic numeral which corresponds to the Arabic numerals on the detailed key maps (Figs. [5]-10, at end of book).
For each feature which bears a place name and for each longer legend on the Leardo map the transcription is given below in italic. Many of these transcriptions, particularly of names written on edifices (castles, churches, etc.), are mere guesses, owing to the obscurity of the original. Particular difficulty was encountered in distinguishing between the letters a, e, o, c, and t, and between s and f. A clue to the reading of many names, however, was furnished by other maps contemporary with or earlier than that of Leardo. Illegible letters are indicated by dots; doubtful readings by (?); interpolated letters are enclosed in square brackets. Illeg. means “wholly illegible.”
No data beside the transcriptions are given for such names as f. tigris, corsicha, galizia, etc., the meaning of which is obvious.
In the case of the less familiar names, the forms in which they appear on certain other medieval maps are supplied. In general, if a name occurs on the Catalan Atlas of 1375 (CA), on the Catalan map in the Este Library at Modena (CE), or on the Ptolemaic maps (Ptol.), no attempt is made to indicate its occurrence elsewhere.
Each doubtful identification with a medieval name is preceded by ?. For names along the coast of the Mediterranean, the Black Sea, and the Atlantic, references are given to the pages in Kretschmer’s Die italienischen Portolane des Mittelalters (= Kret., Port.) where the variant spellings of these names as they are found in the more important portolans and portolan charts are listed and the places identified with modern localities.
Identifications with modern localities are indicated by =, or =mod.; with well-known ancient localities by =anct. Suggested but doubtful identifications are preceded by =?, and names for which I have been unable to find or to suggest any identification with a modern locality are indicated by =? standing alone.
With the identification of Ptolemaic and medieval names in the Far East, in Africa, and in Scandinavia, we enter upon a hazardous and controversial field. While in many instances I have indicated identifications that have been made by competent scholars, needless to say, these should not be accepted as final. One cannot but feel that where an identification is based upon mere similarity in sound it is often a case of one man’s guess being as good as another’s. The scope and purpose of the present study does not permit of an exhaustive examination of these questions of detail.
For more complete bibliographical data relating to publications referred to in abbreviated form in the key and for an explanation of the abbreviations, see pp. [63]-67. In bibliographical references volume numbers are indicated in lower case Roman, book numbers in upper case Roman, and chapter and page numbers in Arabic type.
On the key maps where there are long rows of place names the first and last numbers only are indicated, with an arrow connecting them. This is done to avoid overcrowding.
The Arabic numerals are in general placed in positions corresponding to those of the legends on the original. This leads in some instances to the separation of the numbers from the symbols to which they relate (e.g., 73).