Note 17 — ENTRY.

This is the British Museum rule. It will obviously be sometimes impossible and often difficult to determine this point in a library of less extent than the Museum, and the cataloguer must make up his mind to some inconsistency in his treatment of mediæval names, and be consoled by the knowledge that if proper references are made no harm will be done. Against a too great preference for the vernacular Professor De Morgan writes in the preface to his “Arithmetical books:” “I have not attempted to translate the names of those who wrote in Latin at a time when that language was the universal medium of communication. I consider that the Latin name is that which the author has left to posterity, and that the practice of retaining it is convenient, as marking, to a certain extent, the epoch of his writings, and as being the appellation by which his contemporaries and successors cite him. It is well to know that Copernicus, Dasypodius, Xylander, Regiomontanus, and Clavius were Zepernik, Rauchfuss, Holtzmann, Müller, and Schlüssel. But as the butchers’ bills of these eminent men are all lost, and their writings only remain, it is best to designate them by the name they bear on the latter rather than the former.”