"And he said in the sight of Israel, Sun, stand thou still upon Gibeon; and thou, Moon, in the valley of Ajalon. And the Sun stood still, and the Moon stayed, until the people had avenged themselves upon their enemies." Not even a pious query as to why the Lord did not shower down a few more meteorites, rather than disarrange the whole solar system. Such an attitude of the mind renders one incapable of appreciating anything in astronomic research beyond that which can be measured and photographed. The above is a fair illustration of the intolerable attitude of many of those who deny the existence of the canals, or, if admitting them as existent, resort to every expedient to disprove their artificial character. Among the interesting suggestions as to the cause of the lines on Mars is that proposed by Professor W. H. Pickering, who, while admitting that they represent bands of vegetation, believes that they have their counterpart on the Moon, and that both are produced by volcanic forces, the cracking of the surface being the result of internal strain and stress. The fissures thus produced permit the escape of water vapor and carbon dioxide, and thus the natural irrigation of these cracks is effected and growth of vegetation follows. This opinion should have great weight, as Professor Pickering has made a profound study of lunar details, and is one of the foremost authorities on the subject. He has also drawn many of the surface features of Mars, and was at one time connected with the Lowell Observatory. He it was who suggested irrigation to account for the great apparent width of the Martian lines. In the "Annals of the Harvard College Observatory," Vol. LIII, No. 14, Professor Pickering presents a study of a crater on the Moon's surface, known as Eratosthenes, accompanied by drawings and photographs of an area within the crater revealing a few irregular cracks which he thinks correspond to the well-known canals of Mars; indeed, he calls these lines canals though he believes them to be cracks. A few spots, probably craterlets, he compares to the oases of Lowell. That there is no atmosphere on the Moon is admitted by all. Professor Pickering's keen eye has, however, detected a change in the appearance of these cracks which he attributes to vegetation, animated in its growth by water vapor and carbonic acid gas, as before remarked. In this supposition he may be right, though it seems difficult to believe that so deliquescent an organism as a plant could withstand a variation of temperature from two to three hundred degrees below zero, to one above that of boiling water. One might naturally ask why the greater cracks so conspicuous on the Moon's surface, typical examples of which are found in the Mare Serenitis, Mare Triangulatis, and surroundings, do not emit aqueous vapor and carbon dioxide, and thus show similar features of widening and change of shade. Admitting the correctness of