Chap. IV. THE FATA MORGANA. 483 
the "Dry Lagoon;" the Spanish name is "Las Playas." 
There are, however, in this part of the country, two similar 
localities. We found the bed covered with a smooth layer 
of gypsum, which is dissolved by a periodical overflow : it 
solidifies again, after the drying up of the waters, and 
crystalizes in parts. The road passes over this. The gyp- 
sum was so hard that the wheels made little impression, 
and in many places the surface shone like a mirror. I 
cannot tell whether this space is annually covered with 
water, or only at longer intervals and under unusual cir- 
cumstances — I suspect the latter is the case : at all events 
the bed never fills above a few inches with water, as the 
vegetation on the banks and on the small islands shows 
clearly. 
It was high time that we reached some water on the 
other side. The store in our casks was quite exhausted. In 
a hot atmosphere, our animals had not tasted drink for 
the last forty-eight hours, while the men too were tormented 
with thirst. For the first time I felt the tantalizing effect 
of the Fata Morgana, which led us to imagine the presence 
of water. I had read much of this phenomenon, and had, 
during my travels, seen it a hundred times, but never 
when suffering from extreme drought. This country ex- 
hibits many enigmatical phenomena. On the other side 
of the Dry Lagoon, we came to a luxuriant grassy plain, 
with a large number of deep round holes, filled with water 
as clear as crystal. The level of the water is considerably 
higher than the Dry Lagoon, and yet no brook flows in the 
direction of it. The water-holes are in parts so large and 
deep, that some mules, which tried to drink on the edge, 
and fell in, disappeared for a time under water ; on coming 
to the surface again, we were obliged to drag them out with 
cords. At the edge is a perpendicular slope of turf, which 
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