of the Fishery Board for Scotland. 



267 



observations at anchor off Cuill at the head of the loch for six hours 

 (Table III.). Returned to Inveraray at night. 



September 4th. — Observations at Inveraray, Strachur, Furnace, Minard, 

 Gortans, Loch Gair, Otter, and Kilfinan, including cross-sections at 

 Inveraray, Furnace, and Minard. Returned to Inveraray at night (see 

 Tabl 3 VI.). 



September bth. — Made a series of temperature cross-sections off Furnace 

 at high tide, half-ebb, and low-water (see Table IV.). Returned to 

 Inveraray at night. 



September Qt/i. — Sunday. 



September 1th. — Observations at Inveraray, Strachur, Furnace, Minard, 

 Gortans, Otter, Kilfinan, and Skate Island in the Arran Basin, staying 

 at Millport for the night (see Table VI.). 



September 8th. — Observations at anchor off Otter Spit for nine hours 

 lay for the night in Otter Bay (see Table V.). 



September \)th. — Observations at anchor off Otter Spit for six hours 

 (see Table V.), then observations at Gortans, Furnace, Strachur, and 

 Inveraray (see Table VI.). Stayed at Inveraray for night. 



September 10th. — Observations at usual stations along the whole 

 length of Loch Fyne, from Cuill to Otter (see Table VI.). Staying at 

 Inveraray. 



September 11th. — Observation at Furnace. Spent some time in 

 looking for deep sounding off Pennimore Poiut (marked 82 fathoms in 

 Admiralty Chart), but could not rind more than 75J fathoms anywhere. 

 Returned to Inveraray at night. 



September 12th. — Left the 'Garland' at Gourock. 



General Thermal Condition in September. — This trip resulted in 

 the accumulation of a considerable amount of data, which confirms 

 and extends the conclusions arrived at from my earlier work on 

 Loch Fyne. Table VI. gives the readings of 49 temperature soundings 

 taken to determine general distribution. It is useful, in the first instance, 

 as settling the general distribution of temperature throughout the mass 

 of the water, by means of a longitudinal aud several cross-sections on 

 two occasions six days apart, and so of allowing the time-changes of 

 temperature to be closely followed at the period of the annual maximum. 

 In the Arran Basin the mass of the water had a temperature varying 

 from about 55° at the surface to 50° at 80 fathoms. On the 4th the 

 Gortans Basin was filled with nearly homothermic water averaging 53° '8 

 in temperature ; but inside the Minard bar the Upper Basin was filled 

 with colder water, sinking from the surface warmth to 50° at 25 fathoms, 

 49° at 30 fathoms, and 46° T on the bottom in the deepest part (75 

 fathoms). This coldness of the deep water in Loch 'Fyne in summer is 

 one of its most interesting features, and is always found. The lowest 

 temperature at the bottom of the great hollow of the Arran Basin, 

 off Skate Island (105 fathoms), was only 49°*6, i.e., 3°'5 higher than at 

 the bottom of Loch Fyne. The water on the broad platform, 35 fathoms 

 deep, which stretches between the Minard bar and the sudden dip to deep 

 water off Furnace, was warmer than that at any other point along the Upper 

 Basin ; and just off Furnace the warm incoming water was nearest the 

 cold deep layer, and the temperature gradient was steepest. Thus, water 

 at 52° was found at 25 fathoms near Minard, 18 fathoms at Furnace, 

 10 fathoms at Strachur, 8 fathoms at Inveraray, and 5 fathoms at Cuill, 

 close to the head of the loch. This seaward dip of the isotherms was less 

 marked at lower depths. The surface of the loch from Gortans to Inver- 

 aray was covered with a uniformly thick layer of water, 2 fathoms deep, 



