14 
years ; and when Cuvier was in England, I saw him frequently, and one Sun- 
day evening I was with him, and whilst we were talking of the Bible and 
modern science, he said this “ AH my researches have brought me to this 
conclusion, that the geological changes on the earth do not require a longer 
period for their accomplishment than 6,000 years ’’-the period which we 
think is the duration of the world from the beginning, as we gather trom the 
first chapter of Genesis. I will now invite discussion on the paper, and any 
gentleman who has anything to say will please address the meetmg. . 
Mr. Warington. — Before I commence my remarks on this paper 1 wis 
to ask one question. I was in hopes that the author would hare been here 
to answer it, but X dare say, though he is not here, some other gentleman 
better acquainted with astronomy than myself may be able to solve my 
difficulty. It is this. Mr. Hopkins states that the direction in which the 
crust of the earth is moving, is at the angle of 23£ degrees to the Equator, 
that is to say, in the same angle as the line of the ecliptic ; and he says that 
this is equivalent to an annual motion in latitude of 20 seconds, and in 
longitude of 50 seconds ; in other words, the proportion is as two to hve. 
Now, upon looking at the globe, and seeing what relation there is between 
the changes of latitude and longitude involved in the motion of the ecliptic, I 
find instead of these changes being in the proportion of two to five, they are 
in the proportion (nearly) of two to eight. How is this to be explame . 
■Which is right 1 Is the motion really a motion in the plane of the ecliptic 
at an angle of 23J degrees, or is it a motion in the proportion of two of lati- 
tude to five of longitude— that is, at an angle of 36 degrees ? I want to use 
these figures in testing Mr. Hopkins’s conclusions, and until I know which 
method of reckoning is right I am altogether at sea. Is there any one present 
who can help me ? If so, I should, be glad if they would do so before I say 
another word. 
Rev Walter Mitchell.-I think, perhaps, Mr. Warmgton may be 
labouring under a misconception. There is some degree of vagueness on that 
rtoint in the paper ; but I think that astronomers admit there are two 
motions, or one motion, in reality, which is resolved into two. One of these 
motions is accounted for by a gradual change of the point at which the 
ecliptic cuts the Equator. That is the motion by which the plane of the 
earth’s motion round the sun is slowly changing ; but that is not sufficient to 
account for all the changes. Besides that, which is called the precession of 
the equinoxes, there is another change, and that is accounted for by what is 
called “ nutation,” consisting of a wriggling motion of the earth s axis, as it 
were, in space. While the plane of the motion is changing, you have a 
change like the motion of a teetotum ; and the whole change that takes 
place is compounded of these two motions. It was the popular theory a 
little while since-the generally received theory of all the text-books on 
astronomv — that there was no real motion of the earth’s crust but that the 
only motion was a change in the earth’s axis occasioned by the disturbmg 
forces of the moon and planets upon the earth. There is now a growing 
belief on the part of astronomers, including the Astronomer Royal, that the 
