endured the torture long enough, and had managed to take a
satisfactory solar observation, you generally had to remove all your
clothes in order to get rid of the unpleasant parasites--and you then had
a good hour's hard work cut out for you.

[Illustration: Quadrangular Rocky Mountain showing Rocky Wall
connecting it with the Neighbouring Range.]

[Illustration: Author's Caravan in the Heart of Matto Grosso.]

We continued our march northward, the temperature in the sun being 105 deg.
Fahr. The minimum temperature had been 60 deg. Fahr. during the night of June
17th, and 64 deg. on June 18th. We crossed the Piraputanga River, flowing
into the Rio Manso, and then passed over a magnificent flow of yellow,
red and black lava, the Cambayuvah River, a tributary of the Palmeira.

The Cambayuvah flowed through a great volcanic crack 75 ft. high, the
sides of the crack showing much-fissured strata in a vertical position. A
smaller streamlet entered the Cambayuvah where we crossed it. Wonderfully
beautiful, indeed, were the rapids among brilliantly coloured red and
yellow rocks, the water winding its way among high upstanding pillars and
sharp blades of laminated rock.

A beautiful waterfall tumbled over with a great noise into a pool,
scooped out of an immense block of such hardened rock that even the force
of that violent stream seemed to have had but little erosive effect upon
it. The edges of it were as sharp as possible, instead of being worn
smooth and rounded by the constant rapid flow of water. The rock had been
hard baked, and was of a shiny black colour, almost as shiny as crystal.
At the bottom of those picturesque rapids was a circular volcanic vent,
the periphery of which had been blackened by the action of fire. The
Cambayuvah followed a general course of south-east to north-west.

We camped near that enchanting spot--most picturesque, but terrible for
my animals, as the grazing was poor. My mules, when let free at the end
of the march, stood helpless around the camp, looking reproachfully at
us, and making no effort to go far afield in order to get something to
eat. The poor things were quite exhausted. I saw well that they could not
last much longer. My men were constantly worrying me, and saying that we
were going to sure perdition. They had become painfully home-sick, and
had they not been dead-tired too--more so, perhaps, than the mules and
horses--I should have expected great trouble from them. As it was