30 
ocean taking up its final position as an ocean, this mighty 
vapour envelope must have retarded the escape into space of 
the cosmical heat of the earth millions of ages after the moon 
had assumed its final condition as to temperature. 
Therefore it is from such considerations I am led to the 
conclusion that the surface features and details of the moon 
present to us a sight of objects the antiquity of which is so 
vast as to be utterly beyond the power of language to express, 
and scarcely less so for the mind to conceive. 
But yet at the same time such considerations appear to me 
to enhance so vastly the deep interest which ever attends 
the examination and contemplation of the moon’s wonderful 
surface, that I would earnestly urge those who agree with 
the soundness of these views to bear them in mind next time 
they have an opportunity to behold the marvellous details of 
the lunar surface, as I am fain to think that in doing so the 
interest of what is there revealed to them will be rendered 
vastly more impressive. 
The President read a paper “ On the Composition of the 
Atmosphere.” He believed that his inquiry proved that the 
oxygen test was a very valuable one, as indicating the con- 
dition of the atmosphere. The oxygen was diminished in 
many cases, and indeed in all cases where the air was known 
to be inferior. He said the objection to such air may 
perhaps be found not so much in the absence of oxygen as in 
the gases which take its place. That place was not wholly 
supplied by carbonic acid. He believed it needful to examine 
the composition to the second decimal place in the case of 
oxygen, and to the third or even fourth in the case of carbonic 
acid, as extremely small amounts of some gases affect us. 
