Or a work which is chiefly founded on information derived from manuscript or printed sources, little explanation can be necessary. The original intention was, to cast into the form of a Glossary as many of the terms now obsolete, but employed in mediæval chronology, as could be obtained by a diligent research, and to assign the bearing of each, as nearly as it could be satisfactorily ascertained. In the prosecution of this plan, it soon became obvious that the utility of the Glossary would be considerably enlarged by determining the age of the term itself; and the attempt to effect this object with exactitude has necessarily introduced a multitude of ecclesiastical and legal antiquities, which were not contemplated in the first design, but which are indispensable in many cases to confer probability on explanations, respecting which there may be conflicting opinions. Writers of considerable eminence on ecclesiastical subjects connected with chronology, do not always agree in determining the year in which several of the principal festivals were instituted. The variation sometimes extends to one or two centuries, and occa sions difficulties which are not always to be surmounted. In such cases, the leading opinions are given, with references to the authorities on which they are founded. As historical events sometimes, and legal instruments of any pretence to antiquity frequently, have no other indications of their date than the name of a day, or of a religious ceremony of periodical occurrence, a useful approximation to the year may very often be obtained from a knowledge of the origin of the name by which the event or instrument is dated. In history, we sometimes find important events dated by moveable feasts, which are readily ascertained by the tables of Golden Numbers, Dominical Letters, and the thirty-five Easters, with that of the feasts themselves, when the year is known; but sometimes no more is indicated than the feast, as in the date of the death of Constantine the Great, which Socrates places on May 22, and Eusebius on Whitsunday, but neither of them state the year. The methods of determining the time of events so dated are described in the Glossary. English charters anterior to the 18th Edw. I are of frequent occurrence, with no other indication of their date than the name of the day. In order to shew the utility of determining in such a case the date of the name, we may suppose it to be that of the Immaculate Conception, on the origin of which there are discordant opinions. Those authorities which fix the year of its institution in the 14th and 15th centuries, would either be contradicted by the charter, or would prove the charter to be a forgery. Bellarmin thinks that it began to be observed about the year 1130, but this is merely an opinion at variance with others. The Saxon kalendars of the 10th century, at the end of the first volume, contain this festival, and thus the investigation of the age of such a |