and the other Azores. 263 
elesis apparent. It has many of the characters of Tripoli 
It is used by the peasants as an external application for cu- 
taneous diseases, and is undoubtedly beneficial in some par- 
ticular cases, from the quantity of sulphur it contains.” 
* The vicinity of the springs is indicated by the increased 
temperature of the earth, a sulphureous odour, and the es- 
cape of vapour or steam from every crack and fissure in the 
ground. ‘The temperature of the clay continues to increase 
as we advance, and a greater quantity of vapour is at last 
seen slowly ascending from the springs themselves. The 
volumes of smoke and steam rolling upwards from the sur- 
face to a great height; till they are gradually diffused 
through the atmosphere, or mingle with the heavier clouds 
that crown the summit of the mountains, produce a striking 
effeet. The confused, rumbling, and hissing noise, that is 
heard for some time before we arrive in sight of the springs 
increases at last to an incessant and terrific roar, and seems 
to issue from the very spot on which we stand. The earth 
returns a hollow sound, and great caution is required to 
avoid stepping into the pools and streams of boiling water, 
with which its surface is covered. 
The quantity of hot water discharged through the in 
numerable orifices in the ground is prodigiously great, and 
the different streams unite, forming a small river that, 
still hot, joins the Ribeira Quinte. The largest springs 
are termed ‘ caldeiras,” or boilers, and a shallow basin of 
earthy matter has been formed round each of them, by de- 
positions from the water. Much of the water is constantly 
retained within these reservoirs, and its surface is more or 
less agitated by the escape of sulphuretted hydrogen gas, 
and the ejection of the water from below. The tempera- 
ture of some of these springs on the second of December, 
between three and four o’clock P. M. the thermometer 
standing at 63° Farhr’t. the barometer at 29, 4 was as fol- 
lows : 
207°—200°——96°—137°—203° 
190°—134°—170°——73°—114° 
184°—-94°—12.2°—171°—147° 
The basin of the largest spring, particularly designated 
as ‘the caldeire,” is circular, and between twenty and 
thirty feet in diameter. “ The water in this, boils with 
much greater violence than in any other caldeira, and dis- 
