art of Peru.

Beyond that sandy zone we had before us a red plateau with fluted sides.
Great mounds of blackened volcanic sand were quite frequent, the railway
winding its way around immense basins formed by depressions in the land.
Then we entered a beautiful green narrow valley along a streamlet
intersecting the plateau.

From Mollendo the railway gradually rose to an elevation of 2,301 m.
(7,549 ft.) at Arequipa, where I remained for the night.

[Illustration: The Great Inca Ruins of Viraccocha, in Tinta (Cuzco).]

Arequipa was an interesting city with its picturesque arcades, its
magnificent church of Spanish architecture with marvellous ancient wood
carvings, and its prettily-laid-out gardens. I visited the astronomical
observatory of Harvard College, a few miles from the town, where
excellent work is being done in star photography from that eminently
suitable spot for the study of the sky. The observatory was situated at
an elevation of 8,060 ft. It worked in conjunction with the Harvard
observatory in North America. By having thus one station north and
another south of the equator, the observations made by that institution
included the stars in all parts of the sky from the North to the South
Pole. A 24-inch Bruce photographic telescope, a 13-inch Boyden telescope,
an 8-inch Bache telescope, and a 4-inch meridian photometer were the
principal instruments used at the Arequipa station.

I left Arequipa on the morning of February 9th, going through country of
volcanic tufa and red sand, with immense furrows quite devoid of
vegetation. Occasionally we came upon great masses of boulders cast by
some volcanic force upon the surface of tufa and sand. Then the railway
gracefully climbed in great curves over a plateau nearly 14,000 ft. high,
where tufts of grass could be seen, giving a greenish appearance to the
landscape.

We travelled along that great table-land, occasionally seeing a herd of
llamas stampede away at the approach of the train, now and then observing
circular stone walls erected by shepherds as shelters. A gable-roofed hut
was occasionally seen. Picturesque natives in their _ponchos_ and red or
yellow scarves gazed, astonished, at the train throbbing along slowly
upon the steep gradient of that elevated barren country. The cold seemed
intense after the tropical heat of Lima. It was snowing hard. In the
daytime I generally travelled seated in front of the engine, in order to
have a better view of the