GEOLOGICAL FORMATION. 
Chap. II. 
sides covered with trees and brushwood, and their 
summits, which form a kind of table-land, all 
under cultivation. The valleys are very fertile, 
and, having a good supply of water, are generally 
used for the cultivation of rice. 
The geological structure of this part of Japan is 
well worthy of notice. In my walks in the country 
I came upon a little hill with perpendicular sides, 
thus forming a convenient object for observation. 
The following is its formation in layers : — 
1st layer. — Vegetable soil : black, resembling peat. 
2nd „ Shells 2 to 3 feet in thickness. Oysters and 
other sea shells. 
3rd „ Gravel. 
4th „ Light-coloured clay, with pumice-stone and 
shells. 
5th „ Blueish-coloured clay, with pumice-stone and 
shells. 
The Yokuhama cliffs are from 60 to 100 feet in 
height, nearly perpendicular, and their structure is 
as follows : — 
1st layer. — Black peaty-looking soil, evidently containing 
much vegetable matter. 
2nd „ Red earth much mixed with gravel. 
3rd „ Gravel. 
4th „ Hard clay. This is intersected here and there 
with a layer of gravel, and sometimes with a layer of shells, 
principally oysters. The shells are seen sticking on the sur- 
face of this layer in all directions. Charred wood and pumice- 
stone are also met with in the clay. 
Springs of excellent water are abundant on all 
the hill-sides. Some of them are deliciously cool 
even in the hottest days of summer, and afford a 
refreshing draught to the weary traveller. 
