TEMPERATURES AND DENSITIES 



OF THE WATERS OF EASTERN CANADA. 



From investigations hy the Tidal and Current Survey. 



The densities and temperatures of the water in the Gulf of St. Lawrence, 

 the Bay of Fundy and other regions off the shores of Eastern Canada and New- 

 foundland, as here published, give the whole of the information of this character 

 which has been obtained to date by the Tidal and Current Survey in these 

 waters. The primary object in view in taking the observations, was to trace 

 the currents and slower movements of the water by these characteristics; and 

 in the various reports on currents issued by the Survey, some partial publication 

 has been given from this point of view. But in the present comprehensive 

 form, it may better serve to indicate the character of the waters themselves on 

 these coasts of Canada, and their variations in regard to locality and to change 

 with the progress of the season. This may also be of value in its bearing on the 

 distribution of fish and other marine life; both locally and during the course of 

 the season. 



The density of the water as here given, is its actual specific gravity. It 

 may be more usual to differentiate sea water in accordance with its salinity; 

 but the specific gravity accords with the totality of dissolved salts which it 

 contains, and it also affords a direct measure of the degree of dilution of standard 

 sea water by fresh water from rivers, which is often a matter of primary import- 

 ance. All the densities given are consistently determined by the same method 

 in the different years indicated ; and they are thus truly comparative throughout 

 the various regions. 



In the three earliest years, 1894, 1895, and 1896, the investigations were 

 carried out with the lighthouse supply steamer Lansdowne, which was placed 

 at the disposal of the Survey for a period limited to three months in each season. 

 In these years, a general examination was made of the currents throughout the 

 Gulf of St. Lawrence, including its connections with the Atlantic ocean through 

 Belle Isle strait and Cabot strait. When the investigation of the currents was 

 resumed in 1903, the surveying steamer Gulnare was commissioned for the work, 

 and eventually equipped with adequate anchorage machinery for greater con- 

 venience; although appliances had already been used for anchoring at Stations 

 in all depths met with, up to 250 fathoms. These investigations were made 

 almost entirely under the personal direction of Dr. W. Bell Dawson, C.E., the 

 Superintendent of the Tidal and Current Survey; with Messrs. H. M. Mackay, 

 and S. C. Hayden successively, as chief assistant. 



Instruments and Methods 



Surface temperatures. — These were obtained with accurate thermometers 

 of Fahrenheit scale, provided with a small ''bucket'' at the lower end, which 

 retained the water around the bulb and protected it from exposure to the air 

 till the reading was taken. They were checked by standard thermometers. 



