Such is the experience every observer of them has had; and success depends upon the acuteness of the observer’s eye and upon the persistence with which he watches for the best moments in the steadiest air. Certain as persistence is to be rewarded at last, the difficulty inherent in the observations is ordinarily great. Not everybody can see these delicate features at first sight, even when pointed out to them; and to perceive their more minute details takes a trained as well as an acute eye, observing under the best conditions. When so viewed, however, the disk of the planet takes on a most singular appearance. It looks as if it had been cobwebbed all over. Suggestive of a spider’s web seen against the grass of a spring morning, a mesh of fine reticulated lines overspreads it, which with attention proves to compass the globe from one pole to the other. The chief difference between it and a spider’s work is one of size, supplemented by greater complexity, but both are joys of geometric beauty. For the lines are of individually uniform width, of exceeding tenuity, and of great length. These are the Martian canals. Two stages in the recognition of the reality confront the persevering plodder: first, the perception of the canals at all; and, second, the realization of their very definite character. It is wholly due to lack of suitable conditions that the true form of the Martian lines is usually missed. Given the proper prerequisites of location or of eye, and their pencil-mark peculiarity stands forth unmistakably confessed. It is only where the seeing or the sight is at fault that the canals either fail to show or appear as diffuse streaks, the latter being a halfway revelation between the reality and their not being revealed at all. Much misconception exists on this point. It has been supposed that improved atmospheric conditions simply amount to bringing the object nearer by permitting greater magnification without altering the hazy look of its detail.[2] Not so. They do much more than this. They steady the object much as if a page of print from being violently shaken should suddenly be held still. The observer would at once read what before had escaped him for being a blur. So is it with the canals. In reality, pencilings of extreme tenuity, the agitations of our own air spread them into diffuse streaks; an effect of which any one may assure himself by sufficiently rapid motion of a drawing in which they are depicted sharp and distinct, when he will see them take on the streaky look. As the writer has observed them under both aspects, and has seen them pass from the indefinite to the defined as the seeing improved, he has had practical proof of the fact, and this not once, but an untold number of times.