In the summer and autumn of last year I paid a visit to Iceland, and I as I had been told by my friend, Mr. Madan, that the difficulty of obtaining large pieces of clear calcspar for optical purposes had been exciting some curiosity as to the state of the quarry itself, and as the peculiarity of the deposit made it an object of interest, I thought it worth while to force Eskirjördhr into my route. The narrow fjords of Sudhrmúla Sysla, of which Reydhartjödhr, the largest, bisects the East coast of Iceland, are cut out of an immense plateau, formed of horizontal sheets of Volcanic rock—chiefly trachyte—between three and four thousand feet high. This has been subsequently eroded into sharp bare ridges with immense cliffs or steep slopes falling from them, parted by torrent valleys and fjords ; the greater part of the district not reaching the present snow-line.