To be fair to Dicuil, we must judge his work not by modern scientific standards but by the standards of the ninth century. We must at least acknowledge that he made a genuine effort to obtain the most accurate available information and that he was more than usually conscientious, for when Pliny’s figures seemed to him to be inaccurate, he left a blank space.[490] In addition to the _Liber de Mensura Orbis Terrarum_, Dicuil is the author of a short poem of twenty hexameters which he prefixed to a copy of a short treatise by Priscian,[491] and of an astronomical work in prose and verse which is still unpublished.[492] This latter is dedicated to Louis the Pious and mentions Dicuil by name. We may therefore infer that this geographer, astronomer and poet was one of the versatile Irish scholars whose work must have contributed in no small degree to the Carolingian revival of learning. This distinguished scholar is believed to be identical with the Dicuil who was abbot of Pahlacht in the ninth century.[493] _Dungal_ is another of those ninth century scholars of whose life the details are all too meagre. From a few fragmentary references and his existing works we are led to the conclusion that he was a very capable man distinguished not only as a theologian and poet but also as an astronomer and schoolmaster.[494] In the year 811 A.D. he wrote a letter to Charlemagne to explain the double eclipse of the sun that was supposed to have occurred the previous year. This letter is written in excellent Latin showing familiarity with Virgil and Cicero.[495] Moreover it shows an intimate acquaintance with the whole field of astronomical literature of the time, but it is chiefly remarkable for the expression of astronomical views that were considered advanced because they seemed to call in question the truth of the Ptolemaic system.[496] In the year 825 A.D. the Emperor Lothair desiring to carry out the enlightened educational policy of his ancestor Charlemagne issued an Edict[497] complaining that through the extreme carelessness and indolence of certain superiors true teaching was shaken to its very foundations, and urging that persons engaged in teaching in all those places hereinafter mentioned should throw all their zeal and energy into securing the progress of their disciples and that they should apply themselves to science as the necessity of the times demanded. He laid out for this exercise certain places chosen in such a manner that neither time nor distance nor poverty might any more serve as an excuse to the people. He desired therefore at Pavia and _under the superintendence of Dungal all students should assemble_ from Milan, Brescia, Lodi, Bergamo, Novara, Vercelli, Tortona, Acqui, Genoa, Asti, and Como.[498] Thus we see what a responsible position Dungal occupied as head of the school of Pavia—the precursor of the famous university.