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THE AMERICAN MUSEUM JOURNAL 



which the Indians in the time of their Incas 

 worked and afterwards were continued by 

 the Spaniards. The veins are large and the 

 metals rich of their kind ; from among them 

 some ores are also taken containing much 

 silver, and all partake of some copper, and 

 on account of this mixture this tin is more 

 showy and hard. ... In the hills of Pie de 

 Gallo of Oruro there is much tin, although 

 not known by many, and because no silver, 

 which all seek, is found there, they pass 

 them by." 



The localities mentioned by Father Barba 

 are in Bolivia on the shore of the great Lake 

 Titicaca or at no great distance from it. 

 From other evidence also, it is clear that 

 Bolivia was rich in tin. This is particularly 

 interesting in view of the fact that the pro- 

 portion of objects of copper containing tin 

 in South America increases from north to 

 south, reaching its maximum in Bolivia and 

 in the high plateau region of Peni. This 

 observation is supported by the analyses 

 made for the American Museum, which 

 show that of fifty-one objects from Chepen, 

 in the northern coast region of Peru, but 

 five contain more than a trace of tin, and 

 only one of these more than four per cent of 

 that metal; and of eight objects from 

 Trujillo, also in the northern coast region, 

 none contains traces of tin. 



On the other hand, of sixteen objects 

 from Cuzco, in the high central plateau re- 

 gion, all except one contain tin, averaging 

 five and one half per cent, and fifty-nine 

 objects from Bolivia are of bronze, averag- 

 ing nearly six and one half per cent of tin. 

 Tin would appear, therefore, to have been 

 made use of especially in those districts 

 where it was easily obtained, and it at once 

 becomes of interest to discover whether the 

 copper ores of Bolivia contain tin as an im- 

 purity, or are found in close proximity to 

 tin ores. 



Although works on metals and mining are 

 not prolific in analyses of Bolivian copper 

 ores, the writer was able to collect enough 

 information to convince him that the old 

 bronze implements could not have been made 

 by smelting impure copper ores. This opin- 

 ion was confirmed by a report i of about five 



' By Mr. R. M. Atwater, .Jr. Mr. Atvvater has 

 spent much time in Bolivia and is familiar with 

 the copper ores and copper mining in that coun- 

 try. He assures me that it is perfectly safe to 

 proceed upon the ground that there does not exist 

 in the mines of Bolivia any natural alloy of copper 

 and tin. or either veins or placers where the two 

 metals occur in such proximity that their mixture 

 could be accidental. 



hundred assays and analyses of Bolivian 

 copper ores none of which showed tin. 



Another fact which seems to preclude the 

 accidental theory of Peruvian bronzes, is 

 that analyses of seventeen specimens from 

 Tiahuanaco, a village of Bolivia, showed 

 twelve of them to be of bronze, with an 

 average of six and a half per cent of tin, 

 while the other five objects — which are 

 clamps used to hold the stones of buildings 

 together — contain no tin whatever. We must 

 believe either that these were purposely so 

 made or that they were the result of acci- 

 dent. Two more clamps from Tiahuanaco, 

 analyzed in 1905,2 also were found free 

 from tin, while four other specimens ana- 

 lyzed at the same time contained six and a 

 half per cent of tin. Only one theory can 

 be advanced to explain the absence of tin 

 in these clamps and that is that they are 

 very much older than the other objects from 

 Tiahuanaco which have been analyzed — that 

 they were made before the discovery of 

 bronze. This seems exceedingly improbable. 



Bronzes from Argentina and Chile pre- 

 sent another phase of this problem, since 

 these countries have no tin deposits. It has 

 been supposed by some archaeologists that 

 the bronze objects found in Argentina were 

 imported from Bolivia, but the discovery 

 later of furnaces, melting pots, molds for 

 casting, and slag in the ancient ruins 

 makes it certain that the bronzes were cast 

 on the spot. Did the prehistoric peoples of 

 Argentina and Chile work tin mines of 

 which we are ignorant, or had they discov- 

 ered copper ores containing a high per- 

 centage of tin of which nothing is now 

 known, or did they obtain their tin of their 

 northern neighbors? The latter theory 

 seems most reasonable. It has been argued 

 by Professor Gowland that when once the 

 discovery was made that metal for many 

 useful purposes could be obtained simply by 

 heating stones of a certain color and weight, 

 there was bound to be a large production in 

 the localities where these stones or ores oc- 

 curred ; and that while these localities 

 natuially must have been the centers 

 whence the metal was supplied to others, it 

 does not follow necessarily that the largest 

 number of metal objects were made alwaj's 

 in or near them, since the crude metal often 



- Adrien de Mortillet, Bronze in South America 

 Before the Arrival of Europeans. Annval Rep. 

 .Smithsonian Instit., 1907. pp. 261-6, Washing- 

 ton. 



