VOLCANIC ASHES AND RED SAND 
In that region the prevalent wind was from the east- 
southeast during the months of May, June, July, and 
August. In September the wind veered gradually to the 
north and northeast; whereas, during the rainy season, 
winds from the north, northwest, and southeast were the 
most prevalent, especially the northwesterly wind. When 
the wind came from the north, it was generally accom¬ 
panied by heavy rain. The rainy season in that particular 
zone of the immense Matto Grosso State extended from 
October to the end of April. 
The Rio Barreiros flowed in a northerly direction 
(elevation 1,500 feet) over a bed of red lava, ashes, red 
earth, and sand. After leaving this river, we quickly rose 
again to an altitude of 1,700 feet upon a first hill, then 
to 1,800 feet on a second, and 1,850 feet on a third 
elevation over a great spur of red lava, extending in a 
graceful curve well into the valley below. 
Exquisite was the view of the great plain below us, 
with its magnificent campos stretching as far as the eye 
could see, far away to the horizon line. In the far distance, 
scattered here and there, rose the peculiar, flat-topped, 
isolated mountains before described. Again all that day 
we marched over ashes, red sand, and volcanic debris. The 
highest point we reached was 1,950 feet. A snake dashed 
across our way among the hoofs of my mule, but no harm 
was done. 
Near Camp Bugueirao (elevation 1,800 feet) where 
we halted, there was a delightful, clear, tiny spring 
emerging from white, volcanic, crystallized rock. Then 
more campos over lovely undulations in the country. 
Close by was what the Brazilians call a furnas (from the 
Latin fornus ), a somewhat misapplied term by which they 
named any deep hollow or chasm, whether vertical like a 
precipice or horizontal such as a cave. 
It was getting slightly less cold during the nights. On 
May twenty-fourth the Fahrenheit thermometer registered 
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