FURTHER EXPLORATIONS IN THE LAND OF THE INCAS 455 



above what is newer. The Spanish con- 

 querors were a race of treasure-hunters, 

 and they and their successors destroyed 

 the majority of the evidence. 



Lack of timber, the prevalence of heavy 

 rains during part of the year, and the 

 ease with which stone might be procured 

 early led to the development of stone as 

 a building material. Strength and per- 

 manence were secured through the key- 

 ing together of irregular blocks. The 

 upper and lower surface of these stones 

 were frequently convexed or concaved, 

 the convexity of one stone approximating 

 the concavity of the adjoining stone. 



Ifi constructing their walls the pure 

 arch was not evolved. They developed 

 several ingenious devices, such as "lock- 

 holes" for fastening the bar back of a 

 door ; "ring stones," which were inserted 

 in the gables to enable the roofing beams 

 to be tied on ; projecting stone cylinders, 

 which could be used as points to which to 

 tie the roof and keep it from blowing off. 

 The ancient builders also provided for 

 ventilation and drainage (see the April, 

 1913, and February, 191 5, numbers of the 

 National Geographic Magazine;). 



pottery like that op greece 



Sculpture in a rude form existed, but 

 no well executed representations of the 

 human body. They had some skill in 

 copying animals' heads, but at best it was 

 crude in comparison to the skill achieved 

 by the coast peoples. A pair of dishes 

 found in Machu Picchu, bearing as deco- 

 ration roughly drawn butterflies painted 

 in three colors, represents their highest 

 attainment in ceramic decoration. 



Their pottery is marked by simple and 

 graceful lines, bearing a striking similar- 

 ity to that of ancient Greece, and resem- 

 bling in its simplicity and utility some of 

 the modern vessels at present in use in 

 French kitchens. 



Owing to the extreme moisture of the 

 climate, the remains of cloth are very 

 few ; but we know that the Inca peoples 

 actually did arrive at a high degree of 

 skill in the manufacture of textiles 

 through their ability to procure the wool 

 of the alpaca. By the use of hand looms 

 artistic and intricate patterns were pro- 



duced, and cloth of the utmost delicacy 

 of texture was not uncommon. 



Their metal articles were easily pre- 

 served, and so we have been able to learn 

 that the people of Machu Picchu were 

 extremely skillful makers of bronze. 



The elaborate study of our collections 

 by Professor Mathewson discloses the 

 fact that the more delicate or ornamental 

 pieces contained the maximum percent- 

 ages of tin, since bronze with a high tin 

 content yields the best impressions in 

 casting. 



Professor Mathewson believes that the 

 early Incas were unfamiliar with refined 

 methods of heat treatment, and so were 

 compelled to sacrifice extra hardness and 

 strength by increasing the tin content in 

 large objects, which required considerable 

 working. Apparently cold working was 

 invariably depended upon to produce the 

 final stiffness and hardness of an object. 

 This necessitated a low tin content in 

 such objects as axes, large knives, etc. 



TREPANNING OE SKUEES WAS COMMON 



Their surgical tools were probably of 

 bronze or obsidian. Surgery appears to 

 have been practiced to a considerable de- 

 gree, if one may judge by the large num- 

 ber of trepanned skulls that we have 

 found in caves within a radius of 25 miles 

 of Machu Picchu. In some cases the cause 

 of the operation appears to have been 

 disease ; in others evidence leads to the 

 conclusion that the operation was in- 

 tended to relieve pain caused by wounds 

 received in battle. Since the favorite 

 weapon of the Inca peoples was the sling, 

 and clubs were common, it is not sur- 

 prising that the skulls of many soldiers 

 should have needed the relief that came 

 from skillful trepanning. 



In the art of war they exhibit skill in 

 defense rather than offense. Fortifica- 

 tions constructed with salients and re- 

 entrant angles so as to admit of lateral 

 fire were not uncommon ; high walls, 

 even dry moats, were not unknown. 

 Forts were frequently located on sightly 

 eminences commanding a fine view of all 

 approaches (see pages 438 and 440). 



They had no machinery and did not 

 use iron or steel. They used levers and 

 inclined planes. They also made huge 



