We are very prone to think that the interests of the men of the Middle Ages were very different to our own, and that they had not the slightest inkling of what were to be the interests of the future centuries. Ordinarily students of science, for instance, would be sure to think that electricity and magnetism, interest in which is supposed to be a thing of comparatively recent years, or at most of the last two centuries, would not be mentioned at all in the thirteenth century. Such an idea is not only absolutely false to the history of science as we know it, but is utterly unjust to the powers of observation of men who have always noted, and almost necessarily tried to investigate, the phenomena which are now grouped under these sciences. Perhaps no better idea of the intense interest of this first century of university life in natural phenomena can be obtained, than will be gleaned at once from the following short paragraph, in which Brother Potamian, of Manhattan College, in his brief, striking introduction to the letter of Petrus Peregrinus describing the first conception of a dynamo, condenses the references to magnetic manifestions that are found in the literature of the time. [Footnote 39] [Footnote 39: The Letter of Petrus Peregrinus, N. Y., 1904.] Most of the writers he mentions were not scientists in the ordinary sense of the word, but were literary men; and the fact that these references occur, shows very clearly that there must have been widespread interest in such scientific phenomena, since they had attracted the {308} attention of literary writers, who would not have spoken of them doubtless, but that they knew that in this they would be satisfying as well as exciting public interest. "Abbot Neckam, the Augustinian (1157-1217), distinguished between the properties of the two ends of the lodestone, and gives in his De Utensilibus what is perhaps the earliest reference to the mariner's compass that we have. Albertus Magnus, the Dominican (1193-1230), in his treatise De Mineralibus, enumerates different kinds of natural magnets and states some of the properties commonly attributed to them; the minstrel, Guyot de Provins, in a famous satirical poem written about 1208, refers to the directive quality of the lodestone and its use in navigation, as do also Cardinal de Vitry in his Historia Orientalis (1215-1220); Brunetto Latini, poet, orator and philosopher (the teacher of Dante), in his Tresor des Sciences, a veritable library, written in Paris in 1260; Raymond Lully, the enlightened Doctor, in his treatise, De Contemplatione, begun in 1272; and Guido Guinicelli, the poet-priest of Bologna, who died in 1276." All of these writers, it may be said, with a single exception, were clergymen, and some of them were very prominent ecclesiastics in their time.