250 Jotyv—On the Origin of the Canals of Mars. 
triple lines. While this agreement of observation and theory is at once a support 
to both, I thus early wish to say that what is advanced in this Paper can claim 
no higher value than that of being a speculation. Until its details have been 
further investigated, and until we possess a more minute knowledge of the 
planet’s surface, it must remain a speculation. But, just because of the desir- 
ability of this further investigation, and as the only rival speculation equally 
comprehensive is the theory of the artificial origin of the canals, I think its 
publication justified. 
It is supposed, in the hypothesis put forward in this Paper, that Mars, at 
various times in his past history, captured small satellites, which, after circulating 
round him for longer or shorter periods of time, fell into him. The phenomena 
of the lines, double or triple, are the result of the proximity of such bodies. The 
captured bodies must have been comparable in size with the larger asteroids at 
present circulating in mean orbits outside that of Mars. They may have been 
something between the dimensions of Phobos and Ceres. The phenomena giving 
rise to the lines would, probably, involve a proximity of less than one hundred 
miles separating the surfaces of planet and satellite. 
The theory further assumes that the axial angular velocity of the planet was 
not always that which it at present is. To account for the differing curvatures of 
the lines, as will be seen later, it must be assumed that Mars’ day was once much 
shorter than at present. It must also be assumed that some of the captured 
satellites were retrogade to the planet’s axial rotation, and some direct; the greater 
number being retrograde. 
A word is to be said in defence of these assumptions on a@ priord grounds. 
The most accredited theory of the origin of the belt of asteroids is, that these 
bodies are a misbegotten world: the débris of a ring of nebulous matter thrown 
off by the Sun before his circumference shrunk to that of Mars’ orbit. This view 
is, of course, the direct application of Kant’s hypothesis to their mode of origin. 
If this represents the facts, then we must suppose that the asteroids were once 
far more numerous than they are at present known to be. According to Proctor, 
it would require 125,000 bodies, having the mass of Ceres, to make up our globe.* 
Only some 400 asteroids, in the mean much smaller than Ceres, are known. 
It is also justifiable to assume that the mass of the nebulous ring, which gave 
rise to these bodies, was comparable with that of the rmg which gave rise to 
Mars, or our Earth. In either case, many tens of thousands of asteroids are 
missing. 
The known asteroids are peculiar in their orbits, both in respect to excentricity 
and to inclination to the ecliptic. The excentricity is so considerable in some 
* “Old and New Astronomy,” p. 554. 
