In approaching the interpretation of the markings of Mars we should first glance at a brief historical summary of what has already been done. We should examine the testimony of those who have seen and drawn the canals; we are then better prepared to examine the records of the latest observations and the explanation of their nature. In the meantime an inquiry must be made as to whether the mathematical astronomer, after all, is best fitted to judge of the surface features of a planet. Next we should take up in the following order the evidences, which are overwhelming, that a network of lines, geodetic in their character, mark the surface of Mars. It has been claimed that these lines show the result of irrigation, and, therefore, the irrigation features of our own planet should be examined. It has been objected that many astronomers have not been able to see the markings, and consequently their existence has been doubted. It will then be proper to point out that the difficulties of seeing are very great, and that the acutest eyesight, coupled with long practice, is necessary to recognize the markings. It has been objected that the drawings of the minuter details of Mars vary with different observers. It will be necessary to show that every kind of research employing graphic representation labors under the same difficulty, and none more so than astronomy. It has been objected that there is not sufficient moisture and atmosphere in Mars to sustain life, and this must be answered by those only who are familiar with conditions affecting life on our own planet. Various theories have been advanced, some of them physical, to explain the markings of Mars, and these must be considered, and, if possible, answered. Comments and criticism are difficult to repress, as the discoveries of Schiaparelli and the additional discoveries and deductions of Lowell have evoked discussions, which, in some instances, have been harsh and unreasonable, and, in one case, positively ridiculous. Schiaparelli has been called an impostor, and Lowell has come in for his full share of vituperation and innuendo. If this portion of the discussion is considered unparliamentary, the attitude and language of certain astronomers have provoked it. A brief account is presented of what the author was enabled to draw of the Martian details, with a transcript of his notes made at the time of observation, and finally a little imaginary sketch is given as to how the world would look from Mars; and if similar kinds of astronomers existed there, what comments and objections they might offer as to the inhabitability of the Earth. Such flights of the imagination are justified in that it gives one a chance to appreciate the weakness of some of the arguments urged against the idea of intelligence in Mars.