SiO Professor Howard T. Barnes [May 31, 



Nearing the Irish coast the variations of the sea temperature 

 became more marked, and this commenced at a distance of 200 miles 

 from the shore. Fig. 7 illustrates this very well, where the vari- 

 ations may be seen to be much larger than in the previous plate. 

 Fig. 8 shows the effect of drawing near the Fastnet lighthouse, 

 which was passed at a distance of about four miles. Here the tempera- 

 ture rose as in the iceberg effect, and then fell as the ship was abeam 

 of the nearest point of land. The temperature then is seen to rise, 

 as land was left behind, through the Irish Sea. The approach to 

 Lundy Island caused the temperature to rise rapidly again and then 

 fall as the ship passed abeam of the island, about 300 yards. The 

 effect is here more marked than in the case of the Fastnet, but it 

 must be remembered that the ship passed much closer in the former 

 case than in the latter. The proximity of the English coast caused a 

 rapid fall of temperature, as shown in Fig. 8, when the ship was 

 only two miles off the Somersetshire coast, steaming up the Bristol 

 Channel. It is probable that the rise of temperature in both cases is 

 due to the effect of fresh water from the land floating out over the 

 surface of the sea, and diluting it to a considerable distance. 



Early in June, since giving this address, I was enabled, through 

 the kindness of the Allan Steamship Hne, to obtain measurements of 

 the sea temperature on the northly route from Ireland across the 

 Atlantic to Cape Race, and through the Gulf of the St. Lawrence to 

 Montreal. These charts, which I intend to publish later, completely 

 confirmed the previous results. During fog in the ice track, the ice- 

 berg effect was clearly obtained, and later a large iceberg was dis- 

 covered ahead. 



The icebergs all produced an effect in the instrument, even those 

 passed at distances ranging from 8 to 12 miles. The temperature of 

 the water through the ice track was between 40" and 41" F. Even 

 when passing within a quarter of a mile of a berg it was only 39°, yet 

 by the iceberg effect — i.e. the sharp rise of temperature to a maxi- 

 mum above the sea temperature — the influence of the berg could be 

 clearly seen. This shows very well that the actual temperature of 

 the water is not a guide as to the proximity of ice, not only because 

 this may be rising and falling, due to other causes, but because in 

 different seasons of the year the Arctic current is at different tempera- 

 tures. The variation of temperature as ice is approached is, however, 

 unmistakable, and this the micro-thermometer has invariably indi- 

 cated. Should the ice be found in a locality where variations due to 

 other causes are found, the iceberg effect is so characteristic and 

 sharp that it will be superimposed on the other curve in such a way 

 as to be unmistakable. 



Nearing Cape Race the temperature fell rapidly several degrees 

 below the surrounding sea temperature. Fresh-water rivers flowing 

 into the St.lLawrence, where the waters were salt, produced the iceberg 

 effect, thus clearly indicating the real cause of that phenomenon as 

 being due to the water from the icebergs diluting the salt water. 



