321 
1909-10.] Current Observations in Loch Garry. 
seen in all the diagrams. All the currents are very uniform in 
direction. 
Fig. 3. 25tli August. The wind had been blowing steadily from the 
east since the 23rd. On the 25th it was of moderate strength. The 
currents were fairly uniform, and a current in the same direction as the 
wind is shown at the bottom of the lake. 
Fig. 4. By 26th August the wind had changed to the west, and the 
current systems seem to have adapted themselves very quickly to the 
change of direction. 
Fig. 5. On 27th August westerly winds continued. The temperature 
discontinuity is not nearly so marked as formerly, because the distribution 
of temperature has been disturbed by the high winds. Probably in conse- 
quence of this the return current is not so marked as usual, and is found in 
deeper water. 
Fig. 6. 2nd September. On 31st August there were strong westerly 
winds, but on 1st September it was nearly calm. On 2nd September there 
was a moderate westerly wind, and notwithstanding the absence of strong 
winds there is found a deep current in the same direction as the wind. The 
surface currents are not strong, and it is surprising that any currents were 
found below the discontinuity. 
It would appear from the observations that high winds do not neces- 
sarily mean strong currents, except, of course, at the surface. Thus the 
considerable velocity of 11 9 cm. per second was recorded on 17th August 
during light winds. On the other hand, the currents on 6th September 
during high west winds were comparatively slow. They were, however, 
very confused in direction, as is seen from the diagrams in fig. 7. 
On 19th August the wind was so strong that only a few observations 
could be made at the centre of the loch. They are shown on fig. 8. 
Though strong, they are very variable in direction. The observations at 
the end of the loch on this date, which have already been referred to, 
also showed very confused currents. Apparently the strong winds had 
the effect of thoroughly mixing the loch. This was shown also by the 
temperature observations, for there was a lowering of the temperature of 
the surface layers and a deepening of the depth of the discontinuity. 
Throughout the observations special attention was directed to currents 
occurring below the discontinuity. Currents were frequently observed 
at the very bottom of the lake, but they were usually variable in direction. 
The currents of 19th August have already been referred to, and though the 
direction of the currents at 180 feet is variable, the average direction is 
westerly, i.e. in the same direction as the wind. The diagrams in fig. 9 
