Barbican also remarked that several large craters, of the class that had no interior cones, reflected a kind of bluish tinge, somewhat like that given forth by a freshly polished steel plate.

These tints, he now saw enough to convince him, proceeded really from the lunar surface, and were not due, as certain astronomers asserted, either to the imperfections of the spy-glasses, or to the interference of the terrestrial atmosphere.

His singular opportunity for correct observation allowed him to entertain no doubt whatever on the subject.

Hampered by no atmosphere, he was free from all liability to optical illusion.

Satisfied therefore as to the reality of these tints, he considered such knowledge a positive gain to science.