The Primaeval State of the Earth 11 



and, finally, on Mars, whose mass is one order less than that of the Earth, the 

 content of hydrogen is so small that this planet has no water and in all probabihty 

 never had any appreciable quantities of it (at the present time an equivalent layer 

 of water on the surface and in the atmosphere of Mars is equal to approximately 

 O'l mm). 



In this connection, of special interest is the phenomenon of vulcanism con- 

 nected with the generation of water vapours on the Moon, a body with a mass 

 two orders less than that of the Earth. At the present time, the mechanism of 

 lunar formative processes is attributed by certain authors [4, 5] (Baldwin, Urey, 

 and others) solely to external forces, namely the falling of meteorites and 

 asteroids up to hundreds of kilometres in diameter. However, most if not all 

 geologists and others attribute this origin to internal forces, that is tectonic and 

 vulcanic processes [6]. Without entering into a discussion of this problem, we 

 may at least point out that there exist on the Moon a large number of formations 

 and pectiliarities of relief which could in no way originate from falling meteorites. 

 Such are the limar domes noted in certain numbers by P. Puiseux [7] when 

 compiling the lunar atlas of the Paris Observatory some fifty years ago, and more 

 recently by Wilkens & Moore; the table mountain Margentin; the polygonal 

 forms on the Moon that are especially developed near the north pole (in the 

 district of Mare Frigoris) and represent hexagons of vertical walls placed 

 directly on the surface of the Moon; the systematic distribution of small craters, 

 especially those located along the ridges of huge circular mountains; the existence 

 of close chains of tiny craters situated mostly on rills or clefts in the lunar soil 

 (the well known hill of Hyginus near the centre of the lunar discs strewn with 

 twenty-three small craters); the tendency of the large craters to form twins; the 

 general conformity between the structure of the craters or the circular moun- 

 tains and the tectonic peculiarities of the surroimding territory, the orientation 

 of gorges, and the like; (one of the best known of such faulted formations 

 and one oriented parallel to the general direction of the gorges in the region of 

 Ptolemy is a vertical wall situated to the northeast of Arzahel;) the existence of 

 bright haloes around some of the smaller craters, especially those situated in 

 clefts and whose origin is apparently due to various gases escaping from the 

 interior of the Moon. One of the most convincing proofs in favour of earlier 

 vulcanism is the existence of orifices at the summits of the central cones of 

 craters which were recently discovered in considerable number by Wilkens & 

 Moore using the 33-in. refractor of the Meudon Observatory [8]. 



All these peculiarities of lunar forms cannot be brought into agreement with 

 the meteorite hypothesis but are in natural accordance with the conception of 

 their tectonic origin. 



On 3 November 1958 N. A. Kozyrev, of the Pulkowa Observatory, U.S.S.R., 

 observed the eruption on the Moon produced by the central mountain of 

 Alphonsus nearly in the centre of the lunar disc. This eruption was followed by 

 emission of carbon compounds registered spectroscopically. 



If it is recognized (and this follows from the above-mentioned facts) that the 

 Moon is capable of exhibiting vulcanism and tectonic phenomena of internal 

 forces associated with the escaping of gases, including water vapours, which 



