EDITORIAL METHOD xxxi the original nor a photocopy is available, we base our text on a previously transcribed or printed version. If more than one such version is available, we select the one that we believe to agree most closely with features characteristic of the author's style, orthography, and punctuation we depart from the text only to correct unambiguous typographical errors. In the case of published items, we take the first version published in the original language as our primary text. For Einstein's publications, we note variations in later editions prepared during his lifetime. If an original manu- script is available, small differences are recorded in footnotes. If the manu- script diverges substantially from the printed version, the dissimilar portions of the manuscript are presented as a separate text, preceding the printed version. When no manuscript, typescript, or printed version in the original language is available, a published translation is used as our text. An English translation authorized by Einstein as the first published version is printed after the German text, if the latter is available. PRESENTATION Published writings and manuscript diagrams are reproduced in facsimile all other material included in this edition is typeset. Texts in each volume are ordered chronologically. Published papers are dated by the date of comple- tion, if known otherwise, by the date of submission or publication. If a tem- poral span is attributed to a document, the earlier date determines its position in the volume. An undated text enclosed with or inserted in another text fol- lows the latter, unless evidence suggests an earlier or later origin. Titles and dates of items in the Writings are noted at the appropriate point in the chrono- logical sequence in the Correspondence. This will also apply to postmarked envelopes to which text enclosures cannot be assigned. Within each volume each text is given a number and an English title. A translation of the original title is used, when such a title exists. Letters are titled, but Einstein's name is omitted when he is the author or recipient. Except in the case of published papers, the text is followed by a descriptive symbol: e.g., "ALS" for "Autograph Letter Signed" (see the List of Descrip- tive Symbols in each volume). If no provenance is specified, the source is the Einstein Archive. Otherwise, the location of the original, in parentheses, fol- lows the descriptive symbol. If the location is unknown, the source of the photocopy or transcript used is given. Symbols for documentary repositories follow the guidelines in The Library of Congress National Union Catalogue (see the List of Location Symbols in each volume).