rni'jii^'roinc imox/i': is soc'r/i amfjuca 



.)(0 



tin-copper Cornish ores' have led to the 

 opinion that none of these ores could be 

 smelted so as to produce a mixed metal 

 consisting only of copper and tin in such 

 proportions as to form l)ronze; and that 

 although the ore might contain a suflicient 

 proportion of tin, it would be iiniiossible to 

 get rid of all the other extraneous ingre- 

 dients without eliminating the tin also. 

 Professor Gowland^ answered these state- 

 ments by preparing a furnace in primitive 

 form, consisting merely of a hole in the 

 ground. In this he smelted a mixture of 

 copper ore (green carbonate) and tin stone 

 and obtained a copper-tin alloy, by which he 

 claimed to have proved in<lisputably that 

 when primitive man smelted a copper ore 

 containing tin a bronze resulted — completely 

 refuting the statement that such ores will 

 yield nothing but copper. Furthermore, the 

 metallic ores within the reach of prehistoric 

 man were undoubtedly those lying near the 

 surface of the ground, in a mineral vein or 

 outcrop. Ores so found are as a rule oxides 

 and carbonates, the most easily reduced of 

 all, and from them metals can be obtained 

 with very little difficulty by treating them 

 in the primitive "hole in the ground" fur- 

 nace above mentioned. 



Now the implements ami ornaments of 

 bronze which have been found in such largo 

 numbers in prehistoric burial places witliin 

 the boundaries of the ancient Peruvian em- 

 pire have caused much difference of opinion 

 and discussion as to whetlier the mixture of 

 copper and tin contained in them was inten- 

 tional or purely accidental. In other words, 

 did the copper which these people mined 

 contain, among other impurities, tin in such 

 proi^ortion as is found in these objects by 

 analysis, or were the two metals separately 

 procured and smelted together with the 

 object of producing a harder metal.' 



With a view to the solution of this prob- 

 lem, 172 analyses of prehistoric copper and 

 bronze objects from Peru and Bolivia have 

 been made for the American Museum of 

 Natural History 'i and for the F'eabody Mu- 

 seum.^ Tlie percentage of tin in these ol)- 



^ See report of Alfred Jenkin. an experienced 

 assayer, published by Sir .lolin Lubbock in Pre- 

 historic Tiriu-s, p. 608. 



- Copper and Its Allo.x s in Pri'liistoric Times, by 

 W. Gowland, Jotirti. Anthmii. Inst, of Grrat 

 Britain and Ireland, Vol. XXXVI, pp. 11-38. 



' By Mr. W. A. Wissler, Dr. Morris Loeb. and 

 Dr. S. R. Morey. 



* By Professor S. P. Sliarples. 



jccts was found to vary from nothing to as 

 high as tliirteen per cent, seeming to pre- 

 clude the ])ossibility of its presence being 

 accidental in most cases. The metals differ 

 remarkably in composition and indicate the 

 possession of considerable metallurgical skill 

 on the part of the inhaljitants of the region 

 from which they came. The absence of the 

 slightest trace of silver seems to prove that 

 the tin was derived from an oxide rather 

 than from the native metal. 



But it is the historical evidence, taken in 

 conjunction with the chemical, which fur- 

 nishes the most interesting data on the 

 question. The early historians, Garcilasso 

 lie la Vega and Father Barba, state posi- 

 tively that the Indians were acquainted with 

 the secret of making bronze. Garcilasso 

 tells us that they "worked with certain In- 

 struments they had made of Copper mixed 

 with a sort of fine Brass." ^ At the time tlie 

 Inca historian wrote, tin was often called 

 brass in Europe as well as in South Amer- 

 ica. Confusion in the names of metals is 

 very old according to Sir John Lubbock, the 

 great English naturalist, who states that 

 "In the Pentateuch, excluding Deuteronomy, 

 bronze, or as it is unfortunately translated, 

 brass, is mentioned thirty-eight times."" 



Early in the seventeenth century Father 

 Alvaro Alonso Barba, whose parish was situ- 

 ated in the very heart of the mining district 

 of Bolivia, and who combined with his duties 

 of priest that of the office of director of the 

 mines, pul)lished a book on Arte de las 

 Mctales. In this he stated that the Indians 

 were acquainted with the use of the tin-cop- 

 per mixture and employed it to give hard- 

 ness to their instruments and arms. Father 

 Barba's intimate relations with the Indians 

 should give great weight to this statement. 

 Another circumstance that should be taken 

 into consideration in estimating the value 

 of his account is the great probability that 

 the parents of some of his Indians must 

 have been living at the time of the Conquest 

 and the facts in the case, therefore, well 

 known in his day. In his chapter on tin he 

 gives the following, which is of interest for 

 comparison with the findings of the modern 

 analysts : 



"Not far from Carabuco, one of the towns 

 l)ordering on the margin of the magnificent 

 Chucnyto Lake, toward the l)orders . . . of 

 Lareeaxa, there are also mines of this metal 



'•Royal Cnmmentnrien. Book 11. cliap. XVI. 

 '^ PrehiMoric Timex, p. 5. 



