490 



NATURE 



\Sept. 28, 1876 



granite piled together in the wildest confusion. The soil was 

 sandy and sterile. Coming to the country of the Ugari he found 

 a tribe almost identical with Unyamwesl. The principal streams 

 of this district fall into the Mulgarazi. Unyamwesi was the 

 commencement of the basin of the Congo. He believed that 

 the natives of Unyamwesi were of the Malay race. They had 

 crossed a great deal with negroes, and had lost the distinctive 

 colour and distinctive marks of the race, but their features were 

 much the same as the dominant races in Madagascar Ugaro is 

 a large plain nearly as flat as a billiard table. The people here 

 were different from the Unyamwesians ; they had not got the 

 same features or the same tribal marks. After passing over the 

 mountains of Komendi, which are an offshoot of the mountains 

 round the south end of Tanganyika, they came to a fertile land, 

 much of it laid waste by the ravages of a neighbouring tribe. All 

 the mountains in that district were of granite. There was there 

 a large quantity of salt and what was remarkable was that the 

 rivers ran perfectly fresh through soil which, when the natives 

 dug wells, gave water which was full of salt. At Ujiji the 

 p'ople are of a different race from those already described, as 

 they shave their hair differently and have not the same features. 

 Along Lake Tanganyika in some places there were enormous 

 cliffs and hollows of rugged granite lying in loose boulders ; in 

 other places the cliffs were of red sandstone, and in others a son 

 of limestone and dolamite. At one place he saw exposed on the 

 shores of the lake large masses of coal. Passing down to the 

 south end of the lake, he found it regularly embedded in cliffs 

 500 to 600 feet high, with waterfalls discharging themselves 

 down the face. Travelling along the side of the lake he came 

 to the Lukogo, a large river more than a mile wide, but partly 

 closed by a sort of sill on which a floating vegetation was grow- 

 ing, a clear passage, however, being left of about 800 yards. 

 After proceeding some four miles up the river, Capt. Cameron's 

 boat got jammed amongst the floating vegetation which grows 

 to the thickness of two or three feet, and it was with difficulty the 

 boat was extricated. The Kasongo country was next reached, 

 the principal characteristic of which was the extraordinary 

 trees, of which boats a fathom wide are sometimes made. 

 Crossing the mountains of Bambara he arrived at Mamyuemba. 

 Here he found the race entirely different from anything he had 

 yet seen. The houses were clifferently built, the people were 

 differently arme^, dressed their head differently, and there was 

 no tattooing to speak of. The villages were built in long streets 

 thirty or forty yards wide, two or three streets being alongside 

 each other, and a space left between the houses, which were of 

 reddish clay with slopmg thatched roof — the only houses of that 

 description he saw in the interior of the country. All the 

 Mamyuemba are cannibals. Journeying northwards, but still in 

 Mamyuemba, a district was reached where iron was very plentiful, 

 and where large forges were at work. Many of the Spears and 

 knives which they turned out looked as if finished off by a file or 

 polished by some means, although all done by hand-forging and 

 patient labour. The Lualaba Kiver was next reached, which is 

 about 1,800 yards in breadth. The southern shore is occupied 

 by a tribe called the Wagenga, who do the whole carrying business 

 of the river, being the only canoe proprietors, who take for pay 

 the products of the country to the different markets. The young 

 women make immense quantities of pottery in the mud and back 

 water, which they exchange for fish. After referring to a country 

 between Nywangi and Loami, where a palm oil grows in great 

 profusion, Capt. Cameron passed through Kilemba, and reached 

 Lake Kigongo. This lake is covered with floating vegetation, 

 on which the people build their houses, cut a space round about 

 them, and so transform their habitations into floating islands, so 

 that when desirable they change the locality from one place to 

 another. Coming to the coast he passed through one of the 

 most magnificent countries in the world to look at, possessing a 

 climate in which any European might live. The Portuguese had 

 been settled in this neighbourhood for thirty years. The whole 

 of this country was just one vast slave field. In the country 

 there was a vast mineral wealth and an ordinary population that 

 with education might be rendered very industrious instead of 

 carrying on a continual warfare against each other ^for the 

 purpose of obtaining slaves. 



An interesting discussion followed. 



Col. R. L. Playfair, H.M.'s Consul-General in Algeria, read 

 a paper On Travels in Tunis in the Footsteps of Bruce. The 

 paperjgave a narrative of the Colonel's observations made in the 

 course of a journey in Tunis over places visited by Bruce about 

 1 763. There had been recently put into Col. Playfair's hand for 

 publication a large number of Bruce's sketches, of which his 



Barbary sketches were, he said, the most interesting, forming 

 about 120 sheets of drawings, completely illustrating the archaeo- 

 logy of North Africa. In these circumstances, the Colonel had 

 determined to follow Bruce in his journey, and to satisfy himself 

 as to the present condition of those interesting ruins which were 

 almost unknown to the modern traveller. 



Mr. A. Bourden read a paper, the object of which was to show 

 that ready access could be had to the Niger and the African 

 interior from Sierra Leone. 



The Secretary, in the absence of the author, read a paper by 

 Lieut. W. H. Chippindali, R.E., containing Observations on the 

 White Nile between Gondokoro and Apuddo. The object of the 

 paper was to establish Lieut. Chippindall's opinion that the oft- 

 repeated assertion that the White Nile could not be navigated 

 higher up than Gondokoro had no warrant in fact. He was 

 sure the White Nile was navigable all the way up to the Aroert 

 Nyanza. 



A paper was read by Staff-Commander Tizzard, R.N., 

 On the Temperature obtained in the Atlantic Ocean, • during 

 the Cruise of H.M.S. " Challenger." Over a great portion 

 of the Atlantic the bottom temperature has this peculiarity 

 — If the depth be less than 2,000 fathoms, we find the 

 temperature at the bottom lower than that of any inter- 

 mediate depth, but when the depth exceeds 2,000 fathoms, 

 we find that the bottom temperatures are nearly the same as 

 they are at that depth. This holds good for three-fourths of 

 this ocean. In the remaining fourth the temperature obtained 

 at the bottom is much lower than in the other parts, and this 

 fourth is not at either extreme, where there is a large current of 

 surface cold, but occupies the whole of the western portion of 

 the South Atlantic as far north as the Equator. The results of 

 these temperatures may be classified th»s : If an imaginary line 

 be drawn from French Guiana to the westernmost island of the 

 Azores and from thence north on the western side of this line, the 

 bottom temperatures at depths exceeding 2,000 fathoms are 35 

 degrees — that is, taking the mean of all the temperatures obtained 

 which differ but slightly. On the eastern side of this line the 

 bottom temperatures are 35*3 deg., and this uniform tempera- 

 ture appears to extend as far south as Tristan d'Acunha, as the 

 German frigate Gazelle obtained similar bottom temperatures 

 eastward of the line joining that island with Ascension to the 

 southward of a line joining Tristan d'Acunha with the Cape of 

 Good Hope. The bottom temperatures are decidedly colder 

 between the eastern coast of South America and a line 

 joining Tristan d'Acunha and Ascension Island ; and from the 

 Equator to the southward the bottom temperatures were invari- 

 ably colder than at any intermediate depth. These temperatures 

 varied from 31 deg. to 33 deg. 5 sec, that is when the depth 

 exceeds 2,000 fathoms, and temperatures of less than 33 deg. 

 were found as far north as the Equator, while a few miles north- 

 ward this bottom temperature was 35 deg. It therefore appears 

 that in the western portion of the South Atlantic the highest 

 bottom temperature is less than the lowest obtained elsewhere 

 in this ocean, excepting where the very low result of 29 was 

 found by the Porcupine in 1869 between the Faroe Isles and the 

 north extreme of Scotland. The question thus arises as to the 

 causes which confines this cold water to the bottom portion of 

 the western half of the South Atlantic. The examination of the 

 soundings which had been taken in this ocean, combined with 

 the results of their temperature, leads to the conclusion that 

 there is a series of ridges dividing its bed into two basins, one of 

 which occupies the whole of the western portion of the North 

 Atlantic, while the other extends the whole of the length of the 

 ocean on its eastern side, and that the cold water in the western 

 portion of the South Atlantic is owing to there being no obstruc- 

 tion between the bed of this portion of the ocean and the bed 

 of the Antarctic basin, and from the results of the serial tempera- 

 tures' soundings it would appear that these ridges cannot exceed 

 l>95o or 2,000 fathoms in depth. To ascertain the thermal 

 condition of the Atlantic (from the surface to the bottom), serial 

 temperatures were obtained in the Challenger at 1 50 positions, 

 observations having been made at each 100 fathoms to 1,500 

 fathoms in depth, and frequently at, say ten fathoms to 200 

 fathoms in depth, at each of these positions. An examination 

 of these temperatures shows that between the parallels of 40 deg. 

 N. and 40 deg. S. there is a much larger amount of warm water 

 in the North than in the South Atlantic, and that in the equa- 

 torial legions the isotherm of 60 deg. is much nearer the surface 

 than in the temperate zones, but that the isotherms below 60 

 deg. are at nearly as great a depth at the Equator as in any 

 part of the South Atlantic, especially at the isotherm of 40 deg., 



