April (), 1874] 



NA TURE 



445 



an extremely flat country, though all 4,000 ft. above the 

 level of the sea. When first discovered I was without 

 paper, but borrowed a little from an Arab, and sent a 

 short account home. I had so much trouble from attend- 

 ants that I took only the barest necessaries. Yet no 

 sooner was the discovery announced at the coast than 

 the official description was forthwith sent to the Bombay 

 Government, that ' the lake is like Nyassa, Tanganyika, 

 and the Albert Nyanza, overhung by high mountain 

 slopes, which slope down to great plains, which, during 

 the rainy season, become flooded, so that caravans march 

 for days through water knee-deep seeking for higher 

 I ground on which to pass the night.' 



" The only mountain slopes are ant-hills, some of them 

 20ft. high. They could scarcely be called high unless 

 thoui^ht of as being built on the top of the 4,000 ft. These 

 statements are equally opposed to the truth, as the Ca- 

 zembe town is built on the banks of the Luapula. 



" People having a crochet for map making traced every 

 step of the Portuguese slaving expeditions to Cazembe, 

 and built the village in latitude S° 43' South — that is, in 

 deep water, near the north end of Lake Moero, and over 

 50 miles from Luapula. I found it in latitude 9° 37' South, 

 and on the banks of a lagoon or loch, having no con- 

 nection with Luapula, which river, however, falls si.x or 

 seven miles west of the village of Moero. 



" Now it is very unpleasant for me to expose any of 

 these misstatements and so appear contradictious. But 

 what am 1 to do ? I was consulted by Sir Roderick 

 Murchison as to this present expedition, and recom- 

 mended the writer of the above as a leader. Sir Roderick 

 afterwards told me that the offer was declined unless a 

 good salary and a good position to fall back upon 

 I were added, as Speke and Grant had, on their pay and 

 I commission. He then urged the leadership on myself as 

 . soon as the work on which I was engaged should be pub- 

 lished. My good, kind-heaited friend added, in a sort of 

 pathetic strain, ' You will be the real discoverer of the 

 source of the Nile.' I don't wish to boast of my good 

 deeds, but I need not forget them. . . ." 



SOUNDINGS IN THE PACIFIC 



RECENT explorations in the Pacific Ocean indicate 

 that its bed is singularly level. The soundings of 

 the U.S. steamer Titscarora, Capt. George T. Belknap, 

 between Cape Flattery and Oonalaska, were described in 

 Nature, vol. viii. p. 150. Upon the conclusion of that 

 cruise, which included also soundings from Cape Flattery 

 to San Francisco, a month was spent in the latter har- 

 bour, and on December 5 a survey was begun between 

 that port and San Diego on the same coast, especially 

 between depths of 100 and 1,500 fathoms. The latter 

 depth or a greater one is reached precipitately along the 

 entire coast of California, at distances of 10 to 70 miles 

 from shore. Off the Golden Gate, in the latitude of San 

 Francisco Bay, at a distance of 30 miles, there is 100 

 fathoms ; at 55 miles' distance, there is a sudden descent 

 from 400 fathoms to a depth of two miles ; at 100 miles 

 out, 2,54s fathoms failed to reach bottom. 



Soundings between San Diego, California, and Honolulu, 

 Sandwich Islands, show that this part of the Pacific is a 

 basin with precipitous sides and a comparatively level 

 bottom. The distance between these points, surveyed by 

 the 7//.vC(7;vMi:, is 2,240 miles. The work was accomplished 

 between January 6 and February 3, favourable weather 

 being experienced during almost the entire voyage. 



In the first 100 miles west from San Diego, there ap- 

 pear to be two valleys and two peaks. The first valley is 

 from 622 to 784 fathoms depth ; the first peak 445 fathoms, 

 the second valley 955 fathoms, the second peak 566 

 fathoms. Thence a precipitous fall takes place, giving 

 in lat. 31^ 43' N., long. 119° 28' W., at 115 miles from 



San Diego, a depth of 1,915 fathoms. After that there is 

 a gentle slope with comparatively unimportant interrup- 

 tions, at the rate of three feet to the mile, to the point of 

 greatest depth, 3,054 fathoms, at a distance of about 400 

 miles east of Honolulu. The sharpest elevation is a rise 

 about midway between the United States and the Sand- 

 wich Islands, in lat. 26° 30' N., long. 127^ 37' W., the 

 highest portion of which is 2,159 fathoms below the sur- 

 face. At the next cast of the lead, the valley to the west 

 of this elevation took 3,650 fathoms. The fall of the side 

 of the basin east of Honolulu is even more remarkable 

 than the descent off the American coast. Fifty miles 

 from Honolulu, soundings gave 498 fathoms ; at 40 miles 

 farther east, in lat. 21° 43' N., long. 156° 21' W., the depth 

 was 3,023 fathoms. Between the last-mentioned point 

 and that of greatest depth a hill rises, on whose summit 

 there are only 2,488 fathoms of water. 



These soundings coincide very nearly with the deter- 

 minations of the depth of the Pacific made on theoretical 

 grounds by the United States Coast Survey in 1854. 

 Those calculations were based on the movements of tidal 

 waves occasioned by earthquakes in Asia. The wave that 

 reached San Fran^ isco had a length of 21c to 217 miles, an 

 oscillation of 35 minutes, and a velocity of 6'o to 6-2 miles 

 per minute. This would give a depth of 2,200 to 2,500 

 fathoms. Similar data wi'h regard to the wave that 

 reached San Diego (having a length of 186 to 192 miles) 

 were calculated as giving an average depth of 2,100 

 fathoms. The average depth of the present soundings is 

 about 2,400 fathoms. 



The bottom is generally a soft, yellowish-brown ooze, 

 better suited in this respect, as well as in being more level, 

 than the route surveyed toward Oonalaska, for a tele- 

 gi-aphic cable. Other considerations of an economic cha- 

 racter, such as prospects of connection with other tele- 

 graph lines, may also serve to overbalance the shortness 

 of the more northern route, and there is much better 

 prospect of fair weather for laying a cable and keeping it 

 in repair in the lower latitudes. 



Surface-temperatures rose from 59"^ F. near San Diego, 

 to 74° F. near Honolulu ; temperatures at 105 fathoms 

 between the same places rose from 50^ F. to 63'' F. 

 These, of course, indicate the equatorial current. At 300 

 fathoms the temperature was constant at 43" F. At 

 bottom, the temperature was everywhere 35° F., except in 

 a single instance where it was 1° colder. The uniformity 

 of temperature below i ,600 fathoms was noticeable. 



One wire has been used in all these soundings, which 

 were made every 40 miles, and the apparatus still works 

 excellently. 



M. CHARLES SAINTE-CLAIRE DEPILLE'S 



WEATHER PROGNOSTICATIONS 

 T^HE prognostications delivered by M. Charles Sainte- 

 -*■ Claire Deville, in his communication of March 2, 

 before the French Institute, were wonderfully fulfilled, at 

 least for Paris, the cold period having had its beginning 

 on the 9th, and its end on the 13th, as was predicted. 

 Public attention was all the more attracted because the cold 

 was manifested by a heavy fall of snow, which was the 

 first of the year. Having recently visited M. Ch. Sainte- 

 Claire Deville, the learned physicist was kind enough to 

 explain everything connected with his theories. 



M. Ch. Sainte- Claire Deville has very often pubhshed 

 similar prognostications which were always successful, but 

 never in so striking a way. He has been a constant com- 

 piler of meteorological records for nearly twenty years ; 

 and being the Inspector-General of the French Meteoro- 

 logical Siations, as well as a member of the French 

 Academy of Sciences, he has consequently at his com- 

 mand an immense number of trustworthy observations. 



He has discovered that there is monthly a large thermo- 

 metrical oscillation, which he calls dodecuple, from the 



