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whole of England were to be submerged, and that certain currents 
operated to take off all the grass land and denude, in one part, all the 
cretaceous downs of Wiltshire ; in another part all the clay lands, such as we 
see around us here ; in another part the slate of Wales ; and in another part 
the bare rocks. And then suppose men to go plumbing down over England 
to take a geological survey of the country at a depth of three miles under the 
ocean by quills full of mud and ooze— what notion would they have of the 
geological formation of England, even if the country were wholly denuded of 
its grass? But what have such experiments done for us? They have 
exploded very many of the old geological theories. What is the proportion 
of the marine fauna of the strata with which we are conversant compared 
with the proportion of the terrestrial fauna of the earth ? What do we know 
of the marine fauna at present existing in the world ? What has been done 
for us by these latter experiments ? They have carried the existing gene- 
ration, as it is called, back to long-past epochs, and not only have we now 
got living animals identical in species with those which are found in the 
cretaceous series, but we have gone down even to the oolites. (Hear, hear.) 
Now I say that all this shows how dangerous it is to argue upon theories which 
are invented to account for the slow accumulation of facts. The accumulation 
of scientific facts is a very hard and a very laborious work ; the invention of 
theories is a very easy, and a very engrossing, and a very seductive kind of 
study. But when you compare what is done by the two classes of workers who 
pursue these two different branches of study, you find that the theorists 
have their work undone by the slow accumulation of facts. Looking at this 
paper of Mr. Pattison’s, I find that to some extent it is based on what I believe 
to be a vulnerable point in the old geology, — I find it is working upon the uni- 
formitarian system, the evolutionary system, and others. Even if we had more 
facts, I do not know that we should ever have sufficient to account for these 
things. People seem to think that if they can only get a few facts they can 
easily account for everything. It is like that celebrated problem,— given, the 
number of a ship’s masts, the shape of her sails, her course, and the price 
and quality of the wood with which she was built, to tell the captain’s name 
and the number of his seamen. (Laughter.) That seems to be like some of 
the things which many so-called scientific men take upon themselves to 
determine. But when we know how very slow is our advance, and how hard 
it is lo arrive at truth with anything like mathematical precision, we should 
always doubt where our data are few, and where there are so many things 
interfering with them that it is difficult to arrive at a decision. Turn for a 
moment to astronomy. Who can say that we know very much of the 
planetary theory? If the orbits of the planets were more elliptical than 
they are, and they diverged from one another more ; if the sun were not 
so extremely large in proportion to the size of the planets, that you must 
include the disturbance of all the other planets with regard to any particular 
one, and then take the mean of disturbance ; if it were not that the orbits 
are nearly circular, you would have to arrive at a planetary theory and a 
