235 
Tuff-cone, Cinder-cone, and 
Lava-stream. 
The several craters differ very much as to the quantity of 
lava that has issued from them. Where the issue of lava has taken 
place only once, breaking through one side of the crater and flow- 
ing over the ring of the tuff-cone to the 
foot of the hill , there we see the volcanic 
system in a very simple perfection and dis- 
tinctness, as at Pigeon Hill near Howick, 
at Green Hill and Taylor’s Hill. At other 
points, however, there was a more copious 
out-flowing of lava; stream followed after 
stream , and the lava-streams of several 
craters uniting together, formed extensive 
lava-fields, upon which it is often a difficult matter to distinguish 
the streams belonging to the different craters. Thus the lava- 
streams of Mount Eden, Three Kings and Mount Albert are 
blended in the large Waitemata lava-field Southwest of Auck- 
land. Those three mountains seem to have been active simultan- 
eously ; their streams , spreading round the basis of the cinder-cones, 
and rolling thence over the northwesterly slope of the Isthmus 
through former ravines and valleys towards the sea. Near the coast 
they met all together in a contracted valley , and there formed one 
large stream to the shore of the Waitemata, terminating on the long 
reef West of Sentinel Rock and opposite to Kauri Point on the 
Northshore. The idea had once been entertained of building a 
bridge from that point across the harbour. 
On the southeastern slope of the Isthmus the lava-streams of 
One Tree Hill, Mount Smart, and Mount Wellington form the 
large Manukau lava-field. Here, however, a remarkable difference 
of age appears in the streams of the various craters , proving 
distinctly that they wore not active all at the same time. The lava 
of One Tree Hill is already entirely decomposed at the surface, it is 
covered with a fertile reddish-brown earth and beautiful grass and 
clover paddocks are laid down over those oldest lava-streams. The 
lava of Mount Smart , on the other hand , presents a stone-field very 
difficult to cultivate; and the comparatively newest lava-streams of Mt. 
