The mast is an
A-shaped contraption, twelve feet high, made of two light poles tied
together and fastened, one to each side of the craft, slightly forward
of amidships. Poles are extremely scarce in this region--lumber has
to be brought from Puget Sound, 6000 miles away--so nearly all the
masts I saw were made of small pieces of wood spliced two or three
times. To the apex of the "A" is attached a forked stick, over which
run the halyards. The rectangular "sail" is nothing more nor less
than a large mat made of rushes. A short forestay fastened to the
sides of the "A" about four feet above the hull prevents the mast from
falling when the sail is hoisted. The main halyards take the place of
a backstay. The balsas cannot beat to windward, but behave very well
in shallow water with a favoring breeze. When the wind is contrary the
boatmen must pole. They are extremely careful not to fall overboard,
for the water in the lake is cold, 55 deg. F., and none of them know how
to swim. Lake Titicaca itself never freezes over, although during
the winter ice forms at night on the shallow bays and near the shore.

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FIGURE

A Lake Titicaca Balsa at Puno
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FIGURE

A Step-Topped Niche on the Island of Koati
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When the Indians wish to go in the shallowest waters they use a very
small balsa not over eight feet long, barely capable of supporting
the weight of one man. On the other hand, large balsas constructed
for use in crossing the rough waters of the deeper portions of the
lake are capable of carrying a dozen people and their luggage. Once
I saw a ploughman and his team of oxen being ferried across the lake
on a bulrush raft. To give greater security two balsas are sometimes
fastened together in the fashion of a double canoe.

One of the more highly speculative of the Bolivian writers, Senor
Posnansky, of La Paz, believes that gigantic balsas were used in
bringing ten-ton monoliths across the lake to Tiahuanaco. This
theory is based on the assumption that Titicaca was once very much
higher than it is now, a hypothesis which has not commended itself
to modern geologists or geographers. Dr. Isaiah Bowman and Professor
Herbert Gregory, who have studied its geology and physiography, have
not been able to find any direct evidence of former high levels for
Lake Titicaca, or of its having been connected with the ocean.

Nevertheless, Senor Posnansky believes that Lake Titicaca was once a
salt sea