38 TOWN GEOLOGY. [i. 



On the uplands are fields in which the soil is already 

 made. You do not know how ? Then look for a field 

 in which the soil is still being made. There are plenty 

 in every lowland. Learn how it is being made there; 

 apply the knowledge which you learn from them to the 

 upland fields which are already made. 



If there is, as there usually is, a river-meadow, or 

 still better, an asstuary, near your town, you have 

 every advantage for seeing soil made. Thousands of 

 square feet of fresh-made soil spread between your 

 town and the sea ; thousands more are in process of 

 being made. 



You will see now why I have begun with the soil 

 in the field ; because it is the uppermost, and therefore 

 latest, of all the layers ; and also for this reason, that, 

 if Sir Charles Lyell's theory be true as it is then the 

 soils and rocks below the soil of the field may have 

 been made in the very same way in which the soil of 

 the field is made. If so, it is well worth our while to 

 examine it. 



You all know from whence the soil comes which 

 has filled up, in the course of ages, the great sestuaries 

 below London, Stirling, Chester, or Cambridge. 



It is river mud and sand. The river, helped by 

 tributary brooks right and left, has brought down 

 from the inland that enormous mass. You know that. 

 You know that every flood and freshet brings a fresh 

 load, either of fine mud or of fine sand, or possibly 

 some of it peaty matter out of distant hills. Here is 

 one indisputable fact from which to start. Let us look 

 for another. 



How does the mud get into the river ? The rain 

 carries it thither. 



