Proceedings of Learned Societies. 395 



River, and launching them in the Bayanos. Surely it was a dis- 

 credit to the civilization of the nineteenth century that the Indians 

 should be said to pass -with boats from the Atlantic to the Pacific, 

 and that we should never have had the curiosity to verify this fact 

 or explore the only section of the Isthmus of which it could be 

 stated with any appearance of truth. 



General Mosquera (Minister of the United States of Columbia) 

 described the efforts which the Government of his country were 

 making to open a road across the Cordillera at the point mentioned 

 by Mr. Oliphant. This was one out of many enterprises which 

 were now being pushed forward with a view to increase the com- 

 merce between New Granada and Great Britain in the abundant 

 produce of that part of Tropical America. 



May 8. 



On the Temperature and Currents of the Seas between 

 England and India. — Capt. Toynbee recorded the principal ob- 

 servations which he had made with instruments supplied by the 

 Board of Trade, during five voyages to India, leaving England 

 early in July and returning about the middle of April. It was the 

 constant recurrence of certain phenomena in the condition of the 

 sea, in the same place and at the same time of the year, that had 

 led him to think they might be interesting as pointing to some 

 important conclusions regarding the Physical Geography of the 

 sea. He found, in the Atlantic, that the specific gravity of the sea 

 decreased on approaching the equator, a result due to the rains 

 falling between the North-east and South-east Trades ; and in the 

 Southern Indian Ocean, in the rainy season (January and Feb- 

 ruary), the whole ocean was affected by the rains then falling 

 south of the Line. With regard to temperature, his numerous 

 observations during the five voyages threw some light on the cold 

 current which swept in August northward along the west coast of 

 Africa ; this he found reason to conclude curved sharply to the 

 westward shortly after crossing the Line in about I7 3 W. long. : the 

 farther east of this the colder was the water ; once, between 1° 30' 

 to 0° 30' N. lat., he found its temperature to descend as low as 70° 

 (Fahr.),. making the air quite cool and damp. In March this current 

 is of a higher temperature, because it has then flowed from the 

 south after the southern summer. Capt. Toynbee confirmed the 

 views of Towson regarding the direction of the tracks of icebergs 

 in the South Atlantic, and showed that the very low temperature 

 of the sea in Table Bay, sinking to 51° in February, was due to the 

 current setting from the ice-bearing sea, and that this was also the 

 source of the great West African current. A few miles to the 

 south-east of the Cape the sea greatly increases in warmth, and 

 along the parallel of about 40°, running from the meridian of 

 Greenwich to 50" E., there was found in each voyage a succession 

 of lanes of hot and cold water, the hot as high as 67\(Fahr.), and 

 the cold sometimes as low as 40°. Were it not for the rush of 

 warm water down the Mozambique channel, the ice-streams travel- 

 ling north-eastward would not be deflected as now, to the south- 



