412 
colour-print is a copy of those views , as true to nature as possible. 
In order to receive the full impression of that marvellous freak of 
nature, it is necessary to have climbed those steps, and to have 
studied the details of its structure. 
Section through the basin and the terraces of Tetarata. 
a. Main-basin, b. basins upons the terraces, c. Level of the Rotomohana. d. Silicious deposit. 
e. Ground consisting of decomposed rhyolite. 
The silicious deposits coyer an area of about three acres of 
land. For the formation of those terraces, such as we see them 
to-day, doubtless thousands of years were required. Forbes, judg- 
ing by the thickness of the silicious deposits on the great Geyser 
of Iceland, which he estimates at 762 inches, and by the obser- 
vation, that an object exposed to the discharge of the geyser-water 
for the space of 24 hours , is covered witli a sheet of paper-thick- 
ness, has calculated the approximate age of the great Geyser at 
1030 years. Similar calculations might be made also with regard 
to the Tetarata fountain , by examining the thickness of the silicious 
incrustations. 
The flat -spreading foot of the terraces extends far into the 
lake. There the terraces commence with low shelves containing 
shallow water-basins. The farther up , the higher grow the terraces ; 
two, three, some also four and six feet high. They are formed 
by a number of semicircular stages , of which , however , not two 
are of the same height. Each of these stages has a small raised 
margin, from which slender stalactites are hanging down upon the 
lower stage; and encircles on its platform one or more basins, 
resplendent with the most beautiful blue water. These small water- 
