Two Waterfalls in British Guiana

Abstract

ILEFT Georgetown on December 5 in a seaplane piloted by Mr. A. J. Williams. Our first stop was at Tumereng, on the Mazaruni, where we picked up 600 lb.of baggage and equipment, and thenwe set off with the hope of landing as near as possible to Mount Roraima, the 8000-foot mountain at the tri-junction of the boundaries between Brazil, Venezuela, and British Guiana. As we approached Roraima the river became dotted with cascades and was very rough. The closest we could reach was at a point about 50 miles from the mountain on the upper Mazaruni near its confluence with the Kamarang. A party of Indians took us in corials up the Kamarang to the Mission at Waramadong. We spent a few days at the Mission engaging Indians to accompany us to Roraima. From Waramadong we moved on to the Mission at Paruima, and then across the Uitshi river, a tributary of the Kamarang, on to Roraima by way of Venezuelan territory. After climbing to the top of this great mountain we took a new route back to the Kamarang, to investigate some waterfalls whose noise was heard echoing through the forest. We camped with a party of Arekuna Indians who had their village in a remote valley. From our own interpreter we found that they had never before seen a white man. They also had heard the roar of a great waterfall but had never seen it. From the Arekunas' camp I organized a small party of two Indians and myself, and we followed the river into the gorge. Up the valley the sides closed in and became very precipitous. About half a mile from the base the fall was still invisible, but the noise became almost deafening and the walls perpendicular. We finally came out into a clear spot, and looking skywards I saw the brink of the fall; because of a promontory I was not able to see its base. It was raining heavily and photography was almost impossible. Finally I climbed to a steep bank, clinging to shrubs and vines, and by hanging on with one hand and operating my camera with the other, I was able to secure a good photograph. I had no way of estimating the height of this fall, but by comparison with the one discovered later on the Uitshi, a branch of the Kamarang, I judge that they fell from much the same height. Leaving the Kamarang we moved up into the gorge of its tributary, the Uitshi. It was easier here. We not only looked from below, but were able to climb to the brink and make a very careful study of the fall. Fortunately the river was fairly low, at the end of a dry season. The width of the Uitshi at the brink was between 150 and 200 feet. I estimated the height of this fall in several ways. I threw large rocks over the brink into the chasm, watching them carefully and timing their period of fall. It took on the average ten seconds for a large rock to fall from the brink into the chasm below. Applying Galileo's laws of falling bodies we calculated that a rock takes 10 seconds to fall 1600 feet.1 These calculations were later supported by Professor Pilgrim, of Queen's College, British Guiana, on my return to the City.