CLYDE SEA AREA. 29 



Knock the temperature of 44° was reached at 30 fathoms, the surface being at 43°'2, and 

 at Dog Kock at 15 fathoms, the surface being at 43°. Similar evidence of mass-cooling was 

 brought forward by Trip No. VII. in February 1887, when, despite higher temperatures, 

 the general distribution of warmth in the water was very similar. 



Trip XIX., March 1888.— To complete the resemblance between the early Spring of 

 1888 and that of 1886, the air-temperature for March was even lower with regard to the 

 average than that of February, the mean temperature of the air over the Clyde Sea Area 

 being the same (37°'5) for the two months. This trip lasted from March 17th to 31st, 

 with a break from the 24th to the 26th inclusive, and a good general survey of the whole 

 Area was made. The weather varied greatly, the wind being, on the whole, northerly or 

 easterly, and usually light. On the 19th there was a stiff easterly wind with squalls, on 

 the 21st a strong breeze from N.N.E., on the 23rd a fresh north-easterly breeze, sinking 

 to a calm, and on the 28th a gale from the north-east and east, accompanied by a 

 snowstorm. 



In spite of the short interval between this trip and the last, there had been a well- 

 marked and general fall of temperature in the water to the extent of nearly 2° on the 

 average. The deep lochs alone retained water exceeding 43° in temperature, the water 

 in the Channel was just at 43°, in the Arran Basin it scarcely exceeded 42° on the 

 average, and was almost homothermic. Everywhere the conditions of the Spring 

 minimum were being closely approximated to, but the temperature was still evidently 

 falling. The whole Dunoon Basin ranged from 42° to 43°. In Loch Goil there was an 

 intermediate maximum rather over 43° '5, and in Loch Fyne the maximum temperature 

 of the Area, 44°*1, occurred on the bottom. The Gareloch was in every way the coldest 

 division, averaging barely 42°. 



Trip XX., April 1888. — Observations were made on April 3rd, 6th to 10th, and 

 14th, either in dead calm weather or with light breezes from a northerly quarter, except 

 on the last day, when there was a light southerly air. The air-temperature for April 

 was still below the average for the season. 



The water-temperature, so far as the few observations' which were made can show, 

 appeared to be rising after the minimum which must have occurred between this trip and 

 the previous one. In the Dunoon Basin the average temperature of each vertical 

 sounding was about 42° # 5, and in the Arran Basin probably about 42° *3, while in every 

 case the surface was warmer, ranging between 43° and 44°. It is unfortunate that more 

 complete observations were not made at this date, as it seems to have been the nearest 

 approach to a return to the conditions found in April 1886, when the systematic work 

 on the Clyde Sea Area was commenced. On that occasion only there was no indication 

 whatever of any physical difference due to configuration. On the present trip the single 

 sounding in Loch Fyne off Strachur showed the minimum temperature of 43° '0 on the 

 bottom, while at similar depths in the Arran and Dunoon Basins the temperature was 

 42°, or a little less. 



This trip is interesting, because the observations are sufficient to enable a comparison 



