342 Mr. J. F. Whiteaves on Deep-sea Dredging 



were engaged, dredging could only be carried on at intervals, 

 and in several cases the same ground was gone over twice or 

 more. 



On ' La Canadienne' Ave had sixteen successful hauls of the 

 dredge. Of these, four were in 50 fathoms of water or less, 

 seven in between 50 and 100 fathoms, and five in from 100 

 to 200 fathoms. 



On the ' Stella Maris ' we had nine successful hauls. One 

 of these was in less than 50 fathoms, two were between 50 

 and 100, and six between 100 and 250 fathoms. 



The deep-sea mud, in the places examined, is dotted over 

 with (for the most part rounded) masses of rock, usually of Lau- 

 rentian gneiss, varying in size from that of a pea to considerably 

 larger than a man's head. By a modification of the usual 

 sieving process every organism, piece of rock, &c. larger than 

 -^ of an inch in diameter was first picked out from the mud. A 

 large bagful of the mud thus sifted,from each locality examined, 

 was preserved for subsequent microscopic examination. Three 

 fourths of this mud was found to be a silt so impalpable as, 

 when wet, to pass readily through fine cambric ; the remain- 

 ing fourth consisted half of organic, and half of inorganic 

 matter. The organic matter comprised a few diatoms, mul- 

 titudes of Foraminifera, some Polycystina, many sponge- 

 spicules, and fragments of other organisms. The inorganic 

 debris was a more or less coarse kind of sand, made up of 

 fragments of quartz, bits of felspathic rocks, and small flakes 

 of mica. 



Attempts were made to endeavour to ascertain the approxi- 

 mate temperature of the deep-sea mud. When the dredge 

 was hauled up, its contents were emptied as quickly as possible 

 into a large shallow tub ; and this was covered with a tarpaulin 

 and placed in the shade. An ordinary thermometer, with a 

 metal case and perforated base, was then plunged into the 

 mud, and the whole was kept carefully shaded for some time. 

 With one exception, the temperature of the mud was found to 

 be from 37° to 38° Fahr., and this not alone in deep water ; 

 for sand brought up from 25 fathoms, on the north shore of 

 the St. Lawrence, also made the mercury sink to 38° or 

 37° Fahr. In the centre of the river, between the island of 

 Anticosti and the south shore of the St. Lawrence, mud 

 brought up from 200 fathoms only made the mercury sink to 

 from 43° to 45° Fahr. Either a warm current affects the 

 temperature of the bottom at this point, or else my observa- 

 tions were inaccurate or defective, which latter assumption is 

 by no means unlikely. 



On one occasion a somewhat curious phenomenon occurred. 



