proceedings: philosophical society 151 



record of the ocean temperature near the surface was also obtained, 

 and each gave evidence of the location of ocean currents. Charts 

 giving these data and thus locating the Labrador Current and the Gulf 

 Stream in the vicinity of the Great Bank were shown. The density 

 (reduced to 15° C.) of the Labrador Current was about 1.0245, of the 

 Gulf Stream 1.0270; but the actual densities in situ were respectively 

 1.0267 and 1.0266. The width of the Labrador Current at latitude 

 45° N. was 65 miles and at 44° N. only 25 miles. Detail temperature 

 curves showed beautifully the interdiffusion of the two streams at the 

 southern end of the Great Bank. The results in general corroborate 

 the current charts of Captain C. E. Johnston. 



Discussion: Messrs. Sosman, White, and Humphreys discussed 

 the possibility of the Labrador Current diving under the Gulf Stream. 

 Captain Johnston stated that by observing icebergs he had come to 

 the conclusion that the Labrador Current acts like a band; when a 

 great quantity of cold water accumulates it sweeps under the Gulf 

 Stream or breaks through irregularly. Mr. Stillman asked whether 

 it was feasible to measure densities by measuring resistances. Mr. 

 Dickinson stated that salinities could be measured by electrical 

 methods in the laboratory but that difficulties would be encountered 

 at sea. Mr. Swann suggested the use of the string galvanometer for 

 work on board ship. 



Mr. P. V. Wells then spoke on The study of fog at sea. The speaker 

 described the work on fog clone aboard the ice-patrol cutter Seneca 

 during a cruise in May, 1915. The nucleation, the number of persistent 

 nuclei per cubic centimeter, was measured three times daily by the 

 corona method of Barus. The error was less than 15 per cent. Gen- 

 erally the nucleation was high in cyclonic areas, from which it was 

 inferred that the nuclei at sea are mainly salt particles — evaporated 

 spray. The nucleation was never below 400, normally 1000, and three 

 times rose to 50,000. The liquid content, or grams of liquid water per 

 cubic meter, was determined by evaporating the fog electrically and 

 measuring the humidity at the higher temperature. A value, 0.7, 

 with an error of less than 20 per cent, was obtained. The size of the 

 fog particle was 5X10 -4 cm. A rise of 1?4 C. would dispel this fog, 

 and as an inversion of 2?5 was observed at the masthead, the fog- 

 did not extend that high. The speaker suggested the possibility of 

 seeing from the masthead a powerful light or a flag on the masthead 

 of a nearby ship. 



Discussion: Mr. Swann stated that the measured ionization over the 

 sea is about as great as over the land; on land it is possible to account 

 for 5 ions per cubic centimeter, while over the sea it is possible to ac- 

 count for only 1| ions per cubic centimeter. Mr. Wells stated that 

 the nuclei over the sea were less numerous than over the land, which is 

 in agreement with observations of atmospheric electricity. Barus sus- 

 pected a connection between nuclei and ionization; it would have been 

 an improvement had it been possible to observe nucleation and ioniza- 

 tion simultaneously. 



