lands.  One may imagine the dismay with which the agricultural residents of these ancient houses saw their beautiful fields at the bottom of the hill, covered in a few days, or even hours, by enormous quantities of coarse gravel brought down from the steep slopes of Picol after some driving rainstorm.  It may have been some such catastrophe that led them to take up their residence elsewhere.  As a matter of fact we do not know when it was abandoned.  Further investigation might point to its having been deserted when the Spanish village of San Geronimo was founded.  However, I believe students of agriculture will agree with me that deforestation, increased erosion, and aggrading gravel banks probably drove the folk out of Saylla.

The southern rim of the Cuzco Basin is broken by no very striking peaks, although Huanacaurai (13,427 ft.), the highest point, is connected in Inca tradition with some of the principal festivals and religious celebrations.  The north side of the Huatanay Valley is much more irregular, ranging from Ttica Ttica pass (12,000 ft.) to Mt.  Pachatucsa (15,915 ft.), whose five little peaks are frequently snow-clad.  There is no permanent snow either here or elsewhere in the Huatanay Valley.

The people of the Cuzco Basin are very short of fuel.  There is no native coal.  What the railroad uses comes from Australia.  Firewood is scarce.  The ancient forests disappeared long ago.  The only trees in sight are a few willows or poplars from Europe and one or two groves of eucalyptus, also from Australia.  Cuzco has been thought of and written of as being above the tree line, but such is not the case.  The absence of trees on the neighboring hills is due entirely to the hand of man, the long occupation, the necessities of early agriculturists, who cleared the forests before the days of intensive terrace agriculture, and the firewood requirements of a large population.  The people of Cuzco do not dream of having enough fuel to make their houses warm and comfortable.  Only with difficulty can they get enough for cooking purposes.  They depend largely on fagots and straw which are brought into town on the backs of men and animals.

In the fields of stubble left from the wheat and barley harvest we saw many sheep feeding.  They were thin and long-legged and many of the rams had four horns, apparently due to centuries of inbreeding and the failure to improve the original stock by the introduction of new and superior strains.

When one looks at the great amount of arable slopes on most of the hills of the Cuzco Basin and the unusually extensive flat land near the Huatanay, one readily understands why the heart of Inca Land witnessed a concentration of population very unusual in the Andes.  Most of the important ruins are in the northwest quadrant of the basin either in the immediate vicinity of Cuzco itself or on the “pampas” north of the city.  The reason is that the arable lands where most extensive potato cultivation could be carried out are nearly all in this quadrant.  In the midst of this potato country, at the foot of the pass that leads directly to Pisac and Paucartambo, is a picturesque ruin which bears the native name of Pucara.