326 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 39 



In subsequent years the savanna lands in the southwest were pene- 

 trated by settlers, more from the Brazilian side than from the British, 

 and the Essequibo and Rupununi Rivers became fairly well known. 

 Balata bleeders ascended the Courantyne as far as Wonatobo Falls, 

 and a few hardy pioneers, including Barrington Brown, explored the 

 upper Courantyne and its tributary, the New River ; but for the most 

 part very little was known of the southeast corner of the colony. 



In 1901 a treaty was concluded between Brazil and Great Britain 

 whereby these countries agreed to survey and demarcate their common 

 boundaries, defined as follows from geographical information then 

 extant: From Mount Roraima eastward along the watershed to the 

 source of the Ireng River; down the Ireng to its junction with the 

 Takatu River; up the Takatu to its source at Mount Wamariaktawa 

 and thence eastward along the watershed between the tributaries of 

 the Amazon and the several rivers draining British Guiana to the 

 source of the Courantyne. The Venezuelan and Dutch boundaries 

 were also defined. His Majesty the King of Italy was to act as referee. 



However, it was not until 1930 that field work began. In the fol- 

 lowing year a commission, set up by the colony itself, met Brazilian 

 and Venezuelan commissions at Roraima, the western tri junction 

 point. This point was fixed and the survey of the Brazilian bound- 

 ary was commenced. 



On the west side of the colony the mountain plateau drops abruptly 

 to the sand and clay belt in a rock escarpment 1,000 feet high. The 

 rivers draining the plateau and the foothills of the Roraima range 

 plunge over this shelf in falls rarely equaled for height or beauty, the 

 best known being the Kaiteur Falls on the Potaro; there are many 

 others, some higher, but none of such perfect proportions of volume 

 and height. 



To reach the Kaiteur Falls from Georgetown used to mean a 7-day 

 journey by steamer and motorboat. This is now reduced to 3 days 

 by overland transport between Bartica and Garraway Stream, a small 

 settlement on the Potaro; but the most convenient and impressive 

 route is by air. The flight takes 2% hours, and the plane alights on 

 the river above the falls. The take-off for the return flight is an 

 experience itself, for the plane taxis down the river and takes off 

 over the brink of the falls. At one moment the macliine is flying 100 

 feet off the water, the next it is 900 feet up over the mist-filled gorge. 

 It continues down the gorge shut in on either side by steep green 

 cliffs streaked with the white streamers of cascading forest streams. 



The line of communication of the first commission leading to Ro- 

 raima went up the Potaro, and these falls presented an obstacle of the 

 first magnitude. All stores, instruments, rations, and the materials 

 for building boats to navigate the upper river had to be carried over 



