THE POSITION OF GEOLOGY. 539 



But although the assumption of the uniformitarians on the 

 question of degree may be disputed, that on the question of kind 

 admits of no dispute. That rivers excavate and currents dis- 

 tribute the excavated materials, and that the land is mobile and 

 subject to changes of level, no one will contest. The point of 

 contention is the rate at which these operations and changes 

 proceeded formerly as compared with the rate at the present day. 

 The many observations made on the erosive and transporting 

 power of rivers, and on the movements and waste of the land, are 

 admirable in so far as they apply to the silting up of ports, the 

 recession of the coast, and the reclamation of marsh lands ; but, 

 though valuable to the engineer, they are misleading to the 

 geologist. They furnish him, it is true, with standards appli- 

 cable to present changes, and indicate the method in which the 

 erosive power of the rivers and seas has acted in all time, but 

 they give no measure of the amount and rate of work they did at 

 different periods. Nevertheless, knowing what at present is ac- 

 complished by their means, it is reasonable to judge, by ascer- 

 taining what their agency accomplished in former days, of the 

 difference in the forces in operation at the several periods. Those 

 forces have to be estimated by the work done in the past, and not 

 by any fixed rate founded upon present work. 



Few geologists would, we presume, contest this position ; not- 

 standing which, and though many now profess a modified uni- 

 f ormitarianism, the old lines of argument still, with few excep- 

 tions, prevail, and the concessions made are more apparent than 

 real, or are of little value. In our opinion, no partial concession 

 can be entertained on the question of degree. It must be an 

 unconditional surrender ; for, in contradistinction to method, or 

 manner, where we are on common ground, no common scale on 

 the question of degree is possible in judging of the past by com- 

 parison with the present. 



As an example of the present position, we may take one 

 argument as presented by the advocates of the uniformitarian 

 school. The observations on the transporting power of the large 

 rivers of the world have shown that the quantity of sediment 

 carried down by them to the sea is, according to one of their esti- 

 mates, such as would suffice to lower the level of the land about one 

 foot in six thousand years, or about a thousand feet in six million 

 years. Exception might be taken to this estimate in that no ac- 

 count is taken of the calcareous matter removed in solution, which, 

 in fact, is not far from the quantity of insoluble matter carried 

 down mechanically. Let that pass. This measure, or one ap- 

 proximate to it, has been very generally accepted, and is in 

 common use. Hence those geologists, proceeding solely on the 

 assumed postulate, and not attaching due weight to other con- 



