EXCURSIONS ON THE PLANETS? 
By Lucien RupDAUX 
[With 10 plates]? 
May we some day be asked to leave this modest planetary globe 
upon whose surface we now pass our lives? We will not stop to 
discuss the pros and cons of such an eventuality but suppose the 
question has been answered affirmatively. In other words, some 
dweller on our earth is to set foot upon other worlds. Upon such 
a voyage will the reader be conducted. To simplify matters we 
will abstain from any scientific speculations as to the actual itin- 
erary of such a voyage. Let us disdain all ordinary methods of 
journeying, too slow for our purpose, because of the immense dis- 
tances to be traversed. We will suppose ourselves—as our imagi- 
nation can allow us—transplanted in the twinkling of an eye to the 
various neighboring worlds—the moon and the planets of the solar 
system, the “earths of the heavens,” as they have been expressively 
called by Camille Flammarion. 
Can we, by any chance, describe the scenes we will see except as 
pure phantasies? Yes. Within certain limits, we can approach the 
subject and reply positively to some of the questions which will 
be asked in the contemplation of the heavens. If, despite the per- 
fection of the methods of research in modern astronomy, there yet 
remain many unsolved problems relating to an intimate knowledge 
of the celestial worlds, nevertheless we do have at present precise 
data which make possible a visualization of the general physical 
conditions on each of them. That we may keep on ground where 
we are surest of not going astray, we will try to indicate simply 
the essential differences in the aspects of nature which meet the eye 
of the human voyager. 
Let us start on the moon. We know that its surface is broken 
by thousands of rings, or craters, of various depths, numerous moun- 
tains, and vast plains improperly called seas. This general view 
is so well known that we need not dwell upon it. But we must 
consider how all this would appear to a voyager landing upon the 
Translated by permission from La Nature, June 19, 1926. 
* Halftone reproductions of drawings by the author. 
185 
