He rose, and throwing the pen impatiently on the table, went to the little window and looked out.  His shoulders overlapped the opening on both sides as he thrust his yellow head out into the evening sunshine, and Master Simpelmayer, the shoemaker down in the street, glanced up, and seeing that the Herr Doctor was taking his evening sniff of the Neckar breeze, laid down his awl and went to “vespers,”—­a “maas” of cool beer and a “pretzel.”  For the Herr Doctor was a regular man, and always appeared at his window at the same hour, rain or shine.  And when Simpelmayer mended the well-worn shoes that came to him periodically from across the way, he was sure that the flaxen-haired student would not call over to know if they were finished until the sun was well down and the day far spent.  On this particular evening, however, there was no mending in hand for the Herr Doctor, and so the crooked little shoemaker filled himself a pipe, and twisted his apron round his waist, and stumped leisurely down the street to the beer-shop at the corner, where he and his fellows took their pots and their pipes, undisturbed by the playful pranks of the students.

But the Doctor remained at his window, and neither vouchsafed look nor greeting to Master Simpelmayer.  He was not thinking of shoes or shoemakers just then, though, to judge by his face, he was thinking very intently of something.  And well he might, for he had been reading serious stuff.  The walls of his little chamber were lined with books, and there was a small sliding-rack on the table, presumably for those volumes he immediately required for his work.  A rare copy of Sextus Empiricus, with the Greek and Latin side by side, lay open on an inclined desk at one end, and the table was strewn with papers, on which were roughly drawn a variety of mathematical figures, margined all around with odd-looking equations and algebraically-expressed formulae.  Well-thumbed volumes of mathematical works in English, German, and French, lay about, opened in various places, and there was a cracked old plate, half full of tobacco ashes and the ends of cigarettes.  The remaining furniture of the room was simple and poor:  a neat camp bedstead, a boot-jack, and a round mirror, not more than four inches in diameter; a tin tub and an iron washing-stand; a much battered old “schlaeger,” with the colours at the hilt all in rags, hung over the iron stove; and that was all the room contained besides books and the working-table and chair.  It would be impossible to live more simply, and yet everything was neat and clean, and stamped, too, with a certain cachet of individuality.  There were probably hundreds of student-rooms in the town of Heidelberg which boasted no more adornment or luxury than this, and yet there was not one that looked like it.  A student’s room, as he grows up, is a reflection of himself; it is a kind of dissolving view, in which the one set of objects and books fades gradually away as his opinions form themselves, and