Lisboa — Pebbles on the Central Plateau of Brazil. 11 



round the camp in the early morning, while preparations were 

 being made for the day's journey. Our caravan happened to 

 get lost for some time in the palm-groves between the river 

 Borrachudo and Abaete, and on this occasion my attention was 

 attracted by the characteristic shape of the pebbles round my 

 tent, then located in a dry creek bed. The pebbles were of a 

 pyramidal shape, having the edges visibly rounded. From 

 that time until reaching the banks of the Paracatu, my atten- 

 tion was especially drawn towards the shape of pebbles in the 

 diamond alluvial deposits both on the plateau and in the beds 

 of rivers, but the shape just described was not again found 

 among them. In prospecting the Rio do Somno and Santo 

 Antonio in the basin of Paracatu river, more than one thou- 

 sand cubic meters of diamond gravel from different localities 

 were washed without a single facetted pebble being found. 

 There were many diamond washers about who came not only 

 from the Sao Francisco valley, but also from the basin of the 

 Jaquitinhonha, to get work in our party, so that I was able 

 to verify the fact that they had never observed facetted pebbles 

 in any part of the diamond district. 



Circumstances obliged me to return by another route. About 

 six kilometers east of the creek where the first occurrence of 

 facetted pebbles was noticed, on the high plateau that separates 

 the Borrachudo from the Abaete, a second occurrence was met 

 with, and here I gathered ten examples of facetted pebbles, 

 which are described below. There being no detailed maps of 

 the district, it is impossible to precisely define the two locali- 

 ties. The following notes may help to find them. Leaving 

 Morada Nova by the road that crosses a small stream known 

 as the Yereda do Pasto, one reaches the river Indaya, Corrego 

 da Areia and Rio Borrachudo ; from there after reaching the 

 plateau, about 750 meters above sea level and following the 

 watershed about twelve miles, the creek mentioned is reached. 

 As the country is not peopled, it was impossible to obtain local 

 names. The locality where facetted pebbles were again found 

 is exactly on the watershed of the Borrachudo and Abaete, 

 along the highway that joins Morada Nova to Santo Antonio 

 d'Agua Fria, 4400 meters north of the Borrachudo and 26,500 

 meters south of the Abaete, these distances being measured 

 by the pedometer along the highway. 



As no samples were gathered at the first place, I here only 

 describe those of the second one. In both cases, the pebbles 

 were scattered about on the surface of the ground, several 

 decimeters apart and not heaped up, as is usual with gold or 

 diamond gravels. 



The facetted pebbles. — As a rule the pebbles have one very 

 rough and flat side, which, being the largest, serves as the base 



