The sources for the parts of the Observator in Dialogue reprinted here are Volume I of the first collected edition published in 1684, and Volume III, published and bound together with Volume II in 1687, both in the collection of the William Andrews Clark Memorial Library. The pieces reprinted from Volume I consist of the prefatory "To the Reader," and Observator Nos. 1, 13, and 110; the papers reprinted from Volume III consist of Observator Nos. 88 and 202. In this edition the following editorial changes have been made: black letter type is indicated by underlining; inverted letters have been corrected; obvious compositor's errors have been corrected; and inconsistencies in font due to compositors' carelessness have been normalized. The frontispiece to this facsimile reprint is reproduced from the Clark copy and measures approximately 13-7/16" x 8-5/8" in the original.