admirable way and with remarkable success, using
aqueducts for irrigation, and employing guano as one of their most
important fertilizers. Europeans learned from them the value of this
fertilizer, and its name, _guano_, is Peruvian. The remains of their
works show what they were as builders. Their skill in cutting stone and
their wonderful masonry can be seen and admired by modern builders in
what is left of their aqueducts, their roads, their temples, and their
other great edifices.

They had great proficiency in the arts of spinning, weaving, and dyeing.
For their cloth they used cotton and the wool of four varieties of the
llama, that of the vicuna being the finest. Some of their cloth had
interwoven designs and ornaments very skillfully executed. Many of their
fabrics had rare excellence in the eyes of the Spaniards. Garcilasso
says, "The coverings of the beds were blankets and friezes of the wool
of the vicuna, which is so fine and so much prized that, among other
precious things from that land, they have been brought for the bed of
Don Philip II." Of their dyes, this account is given in the work of
Rivero and Von Tschudi:

"They possessed the secret of fixing the dye of all colors,
flesh-color, yellow, gray, blue, green, black, etc., so firmly in the
thread, or in the cloth already woven, that they never faded during the
lapse of ages, even when exposed to the air or buried (in tombs) under
ground. Only the cotton became slightly discolored, while the woolen
fabrics preserved their primitive lustre. It is a circumstance worth
remarking that chemical analyses made of pieces of cloth of all the
different dyes prove that the Peruvians extracted all their colors from
the vegetable and none from the mineral kingdom. In fact, the natives of
the Peruvian mountains now use plants unknown to Europeans, producing
from them bright and lasting colors."

They had great skill in the art of working metals, especially gold and
silver. Besides these precious metals, they had copper, tin, lead, and
quicksilver. Figures 65 and 66 show some of the implements used by the
Peruvians. Iron was unknown to them in the time of the Incas, although
some maintain that they had it in the previous ages, to which belong the
ruins at Lake Titicaca. Iron ore was and still is very abundant in Peru.
It is impossible to conceive how the Peruvians were able to cut and work
stone in such a masterly way, or to construct their great roads and
aqueducts