y collected when in a liquid state round some soft matter,
that had subsequently evaporated or disappeared with the intense heat,
leaving empty spaces inside. The laminations were about one-eighth of an
inch thick.

Padre Colbacchini told me that some distance off a curious pool of water
existed which he called the "electric spring." When you placed your hand
in it you received a slight electric shock, while a similar impression to
that of an electric current continued to be felt as long as you kept your
hand in the water.

The mission buildings at Tachos were at an elevation of 1,600 ft., the
observatory, 100 ft. higher. The temperature on May 23rd was max. 81 deg.,
min. 68.4 Fahr. From the observatory hill an uncommon sight was before
us. Seven large and small isolated conical and domed hills stood in
perfect alignment from N.N.E. to S.S.W. in two different sets.

In that region the prevalent wind was from the E.S.E. during the months
of May, June, July and August. In September the wind veered gradually to
the north and north-east; whereas during the rainy season winds from the
north, north-west and south-east were the most prevalent, especially the
north-westerly wind. When the wind came from the north it was generally
accompanied 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 (elev. 1,500 ft.) 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 ft. upon a first hill,
then to 1,800 ft. on a second, and 1,850 ft. 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 ft. A snake dashed across our way among the hoofs of my
mule, but no harm was done.

Near Camp Bugueirao (elev. 1,800 ft.), 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 c