Are the Planets Inhabited?

of the handiwork of intelligent organisms on Mars. In Chapter VII, it was shown that the indispensable condition for living organisms, water in the liquid state, is only occ

a scale by any natural process," his assumption being that he has obtained finality in his seeing of the planet, and that no improvement in telescopes, no increase

curved line as narrow, sharp, and uniform, Beer and M?dler undoubtedly portrayed the planet as actually they saw it. The one marking was named by Schiaparelli the Lacus Solis, the other, the Sinus Sab?us, and they are two of the best known and most easily recognized of the planet's features; so that it is easy to trace the growth of our knowledge of both of them from 1830 up to the present time. They were drawn by Dawes in 1864, by Schiaparelli in 1877 and the succeeding years, by Lowell in 1894 and since, and by Antoniadi in 1909 and 1911. But whereas the drawings of Beer and M?dler, made by the a

refuse to yield to such improvement, and will all still show themselves as uniform spots, precisely circular in outline? It is clear that Beer and M?dler would have been mistaken if they had argued that the apparently perfect circularity of the two oases which they observed proved them to be artificial, because the increase

suppose, if telescopes develop in the future as they have done in the past, that the two hundred oases will preserve their uniformity of appearance any more than the Lacus Solis and the head of the Sinus Sab?us? If a novice begins to work upon Mars with a small telescope, he will draw the Lacus Solis and the

oases than to suppose that an industrious population of geometers have

f the wire was of the nature of defined vision, as would be seen at once if small objects of irregular shape were threaded on the wire; these would have to be many times the breadth of the wire in order to be detected. Again, if instead of a wire of very great length extending right across the field of view of both eyes, a short, black line be drawn on a white ground, it

unless there is a clear space between them of six times that amount. Nearer than that they will give the impression that they form one circular spot, or an oval one, or even a uniform straight line, according to the amount of separation. If two equal rou

heir true outline really defined. It is a question of seconds of arc in the one case and of minutes of arc in the other. Within this range, between the limit at

sensitive screen built up of an immense number of separate elements each of which can only transmit a single sensation. Different eyes will have different limits, both for t

e minimum average distance from its centre to any point situated within it;" therefore, if a small spot be perceived by the sight but be too small to have its actual outline defined, it will be recognized by the eye as being truly circular, on the principle of economy of effort. So, again, a straight line is the shortest that can be drawn

ach other it is not necessary, in order to produce the effect of "canals," that they should be individually large enough to be seen. They may be of any conceivable shape, provided that they are separately below the limit of defined vision, and are sufficiently sparsely scattered. In this case the eye inevitably sums up the details (which

ve the least impression of a true disc; its diameter is indistinguishable; it is for us a mathematical point, "without parts or magnitude." But the image of a star formed by a telesc

urface when viewed through the telescope; that is to say, each point is represented by a minute disc; all l

es, and is received on a plate essentially granular in structure, and is finally examined by the eye. The granular structure of the plate acts as the third f

o have been best favoured by the power of the telescope at their disposal, by the atmospheric conditions under which they worked, and by their own skill and experience-such as Antoniadi, Barnard, Cerulli, Denning, Millochau, Molesworth, Phillips, Stanley Williams and others-have found them to sho

uch ingenuity. But, indeed, there never was any more reason for taking seriously his theory as to the presence of artificial wate

ny oversights in

that there are no large bodies of water on the planet; that the so-called seas are really cultivated land. In t

not supposed that the water needed to travel by way of the canals to the poles. If, however, the moisture is conveyed as vapour through the atmosphere to the pole as winter approaches, it cannot be impossible that it should be conveyed in the same manner from the pole as summer draws on, and in that case the artificial canals would not be needed. If the canals are necessary for conveying t

twentieth part of the water needed for those in the equatorial regions. Another oversight is that of the significance of the alleged uniformity and breadth of the canals. Prof. Lowell repeatedly insists that the canals are of even breadth from end to end, and spring into existence at once throughout their whole length. This statement is in itself a proof that the canals canno

rceived, but not perfectly defined. In 1902 and 1903, in conjunction with Mr. Evans, the headmaster of Greenwich Hospital School, I tried a number of experiments on this point, with the aid of about two hundred of the boys of the school. Th

back of the room could not see anything of them, and only represented the broadest features of the diagram, the continents and seas. Those in the middle of the room were too far off to define the minute markings, but were near enough for those markings to produce some impression upon them; and that impression always was of a network of straight lines, sometimes with dots at the points of meeting. Advancing from a distance toward the diagram the process of develop

myself made privately twelve years earlier, leading me to the conclusion, published in 1894, that the c

rise to a narrow line." Also, "the marvellous appearance of the lines in question has its origin, not in the reality of the thing, but in the inability of the present telescope to show faithfully such a reality." In 1907, Prof. Newcomb made some experiments in the same direction and reached the same general conclusion. More re

to see distinct, well-defined, vertical, parallel white lines, the wood forming the dark background. On getting nearer,

strations of this kind are irrelevant; only observation

very same marking has shown itself as a narrow straight line, uniform from end to end, as if drawn with pen, ink and ruler. The greater distance has caused the irregularities, seen when nearer at hand, to disappear. In this,

ation which has been put upon them. If the planet be within a certain range of distance and under examination with a certain telescopic power, the straight lines and round dot