level of the sea. The second and
shorter branch takes its source from a small lake in the heights of
Carampoma, flows through the valley of San Geronimo, and near San
Pedro unites with the Rimac. The most considerable streams of the
south-eastern confluence are those which rise in the heights of
Carhuapampa, and near Tambo de Viso, flow into the main stream. During
winter the Rimac is very inconsiderable, but when the rainy season
sets in it swells greatly, and in the upper regions, particularly
between Surco and Cocachacra, causes great devastations. In the lower
part where the bed becomes broad and the banks are not much built on,
no considerable damage occurs.

Several small conduits are brought from the Rimac, some for giving
moisture to fields, and others for filling the street trenches of Lima.
The water for supplying the fountains of the Capital does not, however,
come from the river, but from two springs situated 1-1/4 league from
Lima in a thicket near an old Indian settlement, called Santa Rosa, in
the valley of Surco. They are inclosed within a building called the
Puello, or Atarrea, whence the waters are conveyed by a subterraneous
trench to the Reservoir (Caja de Santa Tomas), from which it is
distributed by pipes to 112 public and private fountains. During the
insurrection of the Indians in 1781, which was instigated by the
unfortunate Cacique Don Jose Gabriel Tupac Amaru, one of the sworn
determinations of the participators in that very extensive conspiracy
was to drive the Spaniards out of Lima by artifice or force. Among the
numerous plans for accomplishing that object, I will mention two which
have reference to the water of Lima. One scheme was to poison the whole
of the inhabitants. For this purpose a rich Cacique of the vale of
Huarochirin went to an apothecary near the bridge, and asked for two
hundred weight of corrosive sublimate, saying that he would pay well for
it. The apothecary had not entire confidence in the Indian, but he did
not think it right to forego the opportunity of making a very profitable
sale; so, instead of the sublimate, he made up the same quantity of alum
for the Cacique and received the price he demanded. Next morning all the
water in Lima was unfit for use. On examination it was found that the
enclosure of the Atarrea was broken down, and the source saturated with
alum. The offender remained undiscovered.

The second plan was formed with more circumspection. The conspirat