122 DR HUGH ROBERT MILL ON THE 



I J oil from the Dunoon Basin (Lower Loch Long) at the point where Upper Loch Long 

 begins. Its length is 5 miles, and average width under f mile. The whole area of the 

 water is 3*4 square miles, ami the land drainage is relatively large, being 34 square miles. 

 The ratio of water to total drainage area is 1 : 11*07, the smallest ratio for any of the 

 sea-lochs, except the Holy Loch, which is simply a bay receiving the drainage of 

 Loch Eck, a fresh-water lake. The volume of Loch Goil is 0*037 cubic sea miles, and 

 the tidal increment 0*004. Its mean axial depth is 30^ fathoms, and average depth over 

 all, 14 fathoms. 



The probable volume of rainfall reaching the loch in an average year is estimated at 

 0*02601 cubic sea miles. In 1886-87 it was about 0*01618. 



The average percentage of pure sea-water in the loch is 92*3 



The maximum (in August 1886) was ...... 94*8 



And the minimum (in February 1887) ...... 86*7 



Loch Goil challenges special contrast with the Gareloch, being similar in orientation, 

 indeed it is a continuation of the Gareloch in direction ; but the axis is curved instead 

 of straight, thus presenting a more complicated outline to up-and-down winds. The 

 axis is the same length as that of the Gareloch, the bar is similarly situated and of equal 

 depth in both, and the slopes at the head of the lochs have the same angle, but Loch 

 Goil is twice as deep as the Gareloch. The surrounding hills are much higher, the 

 relative drainage area very much greater, and the normal annual inflow of rain water 

 much greater also. In fact, Loch Goil appears to receive its own volume of rain water 

 on the average in seventeen months, the Gareloch in thirty-six months. In spite of this 

 Loch Goil remains much Salter than the Gareloch, hence there must be a more rapid 

 escape of fresh water, or a better supply of salt, the latter being most likely, as the very 

 deep water of the head of the Dunoon Basin lies immediately outside the bar. 



The particular points of contrast are thus depth, enclosure by mountains, greater 

 salinity, and greater volume of fresh water passing through. 



Comparison must also be made with Loch Fyne, to the Upper Basin of which Loch 

 Goil is, on a small scale, very similar, the station at Stuckbeg strikingly resembling that 

 at Strachur. Loch Fyne, however, requires in normal years forty-five months in order 

 to receive its own volume of fresh water, its drainage area being relatively small. 



Consideration of Loch Goil involves reference to the conditions at the D02; Rock 

 station of Dunoon Basin. 



Observations at Dog Rock, Dunoon Basin. — The position of observing was at the 

 head of the Dunoon Basin, with Dog Rock bearing N.N.E. 4 cables. The depth is 50 

 fathoms, this being the greatest depression of the Dunoon Basin, except that off 

 Gantock. To the north-east the water shoals to the sill of Loch Long, to the west it 

 shoals to the more pronounced sill of Loch Goil, to the south it shallows gradually. 

 See Section 16d., Plate 9 in Part I. The density of the water at this station was as 

 follows : — 



