well as of the beautiful pottery of the Incas.  Furthermore, he has always found time to turn aside from the pressing cares of his large business to assist our expeditions.  He has frequently brought us in touch with the owners of country estates, or given us letters of introduction, so that our paths were made easy.  He has provided us with storerooms for our equipment, assisted us in procuring trustworthy muleteers, seen to it that we were not swindled in local purchases of mules and pack saddles, given us invaluable advice in overcoming difficulties, and, in a word, placed himself wholly at our disposal, just as though we were his most desirable and best-paying clients.  As a matter of fact, he never was willing to receive any compensation for the many favors he showed us.  So important a factor was he in the success of our expeditions that he deserves to be gratefully remembered by all friends of exploration.

Above his country house at Colcampata is the hill of Sacsahuaman.  It is possible to scramble up its face, but only by making more exertion than is desirable at this altitude, 11,900 feet.  The easiest way to reach the famous “fortress” is by following the course of the little Tullumayu, “Feeble Stream,” the easternmost of the three canalized streams which divide Cuzco into four parts.  On its banks one first passes a tannery and then, a short distance up a steep gorge, the remains of an old mill.  The stone flume and the adjoining ruins are commonly ascribed by the people of Cuzco to-day to the Incas, but do not look to me like Inca stonework.  Since the Incas did not understand the mechanical principle of the wheel, it is hardly likely that they would have known how to make any use of water power.  Finally, careful examination of the flume discloses the presence of lead cement, a substance unknown in Inca masonry.

A little farther up the stream one passes through a massive megalithic gateway and finds one’s self in the presence of the astounding gray-blue Cyclopean walls of Sacsahuaman, described in “Across South America.”  Here the ancient builders constructed three great terraces, which extend one above another for a third of a mile across the hill between two deep gulches.  The lowest terrace of the “fortress” is faced with colossal boulders, many of which weigh ten tons and some weigh more than twenty tons, yet all are fitted together with the utmost precision.  I have visited Sacsahuaman repeatedly.  Each time it invariably overwhelms and astounds.  To a superstitious Indian who sees these walls for the first time, they must seem to have been built by gods.

About a mile northeast of Sacsahuaman are several small artificial hills, partly covered with vegetation, which seem to be composed entirely of gray-blue rock chips—­chips from the great limestone blocks quarried here for the “fortress” and later conveyed with the utmost pains down to Sacsahuaman.  They represent the labor of countless thousands of quarrymen.  Even in modern times, with steam drills, explosives, steel tools, and light railways, these hills would be noteworthy, but when one pauses to consider that none of these mechanical devices were known to the ancient stonemasons and that these mountains of stone chips were made with stone tools and were all carried from the quarries by hand, it fairly staggers the imagination.