and journeys without end. Since the majority of the documents of mediæval and modern history are still unedited, or badly edited, it may be laid down as a general principle that, in order to write a really new chapter of mediæval or modern history, it is necessary to have long haunted the great depositories of original documents, and to have, if we may use the expression, worried their catalogues.
It is thus incumbent on every one to choose the subject of his labours with the greatest care, instead of leaving it to be determined by pure chance. There are some subjects which, in the present state of the instruments of research, cannot be treated except at the cost of enormous searches in which life and intellect are consumed without profit. These subjects are not necessarily more interesting than others, and some day, perhaps to-morrow, improvements in the aids to research will make them easily manageable. It is necessary for the student consciously and deliberately to make his choice between different historical subjects depend on the existence or non-existence of particular catalogues of documents and bibliographical repertories; on his relative inclination for desk work on the one hand, and the labour of exploring depositories on the other; even on the facilities he has for making use of particular collections. "Is it possible to do work in the provinces?" Renan asked at the congress of learned societies at the Sorbonne in 1889; and gave a very good answer to his own question: "At least half one's scientific work can be done at one's own desk ... Take comparative philology, for example: with an initial outlay of some thousands of francs, and subscriptions to three or four special publications, a