■[869.] on the Scientific Exploration of the Deep Sea. 437 



ordinary " swabs" used on board ship. An iron rod was attached to the 

 bottom of the dredge, and carried out about two feet on either side of it ; and 

 it was to these projecting portions (resembling the studding-sail-booms 

 extended from a yard-arm) that the "hempen tangles" were attached by 

 Capt. Calver, who rightly judged that if they were attached to the bottom 

 of the dredge itself, they would only bring up what the dredge had passed 

 over and crushed. Though the use of these "tangles" added much to 

 our "hauls" on the Holtenia-ground, especially on a subsequent occasion 

 (§ 86), yet it was on the hard bottom of the Cold area that their value 

 became especially apparent, the "tangles" often coming up laden with the 

 richest spoils of the Ocean-bed, when the dredge was nearly empty (§ 74). 



64. Our course was now directed slowly N.N.W., towards the southern 

 edge of the Faroe Bank, Soundings being frequently taken, that we 

 might determine the boundary in this region between the Warm and 

 the Cold areas. The minimum temperature on the Holtenia-gro\md, 

 as shown by the "protected" Thermometers, was a little under 44°, the 

 depth being 540 fathoms ; and this accorded very closely with the tem- 

 perature of 47°'3 observed in the same spot last year, when the requisite 

 correction was applied for pressure. A Sounding taken on the afternoon 

 of the next day, at Station 49 (Lat. 59° 43', Long. 7° 40'), showed a 

 somewhat less depth, viz. 475 fathoms, and a slightly higher minimum 

 temperature, 4o°'4. In the evening of the same day another Sounding 

 was taken (Station 50), and it was found that the depth had diminished 

 to 355 fathoms, whilst the minimum temperature had risen to 46°*2. A 

 Sounding taken early the next morning, however, at Station 51 (Lat. C0° 6', 

 Long. 8° 14'), showed a minimum of 40°, with a depth of 440 fathoms; 

 and this depression of temperature led us to surmise that we were here 

 passing from the "Warm into the Cold area. The correctness of this 

 surmise was soon proved ; for a Sounding taken at about 20 miles to the 

 north, at Station 52 (Lat. 60° 25', Long. 8° 10'), gave a minimum tem- 

 perature of 30°* 6, though the depth had diminished to 384 fathoms ! 



65. In order to ascertain more particularly the conditions of this very 

 remarkable depression, we requested Capt. Calver to ascertain the tempera- 

 ture at depths progressively increasing by 50 fathoms; and it was thus 

 shown (1) that the minimum temperature is that of the bottom, as had 

 been argued in the 'Lightning' Report (p. 189) to be probably the case ; 

 (2) that this minimum is nearly reached at a depth of 300 fathoms; (3) 

 that the decrease of temperature is by no means uniform, but that whilst 

 it takes place in the first 200 fathoms at nearly the same rate as in the most 

 northerly stations previously tested in the First Cruise, there is a rapid 

 and extraordinary diminution, amounting to more than 15°, between 200 

 and 300 fathoms. (See Table I. p. 456.) This diminution can scarcely be 

 accounted for on any other hypothesis than that of a stream of frigid water 

 passing under the warmer and more superficial stratum. — It is worthy of 

 note that in this spot we found evidence, in the rounded form of the stones 



