THP] FRESH-WATER LOCHS OF SCOTLAND. 
417 
The electrical thermometers were at first intended to furnish the 
means of observing continuously radiation into and from the loch. 
The apparatus was not altogether suitable for this purpose, and, being 
the first installation of its kind in this country, many unforeseen 
difficulties arose in the manipulation of the instruments, but never- 
theless many valuable observations were made by its means. The 
installation consisted of three platinum resistance thermometers and 
a Callendar recorder. The boat-house of St. Benedict's Abbey was 
made available to the Lake Survey by the Lord Abbot of the monastery, 
and in it were placed the recording instruments. A four-ply cable 
connected the recorder with the Ehoda, which was anchored at a 
distance of about 300 yards from the boat-house. Many of the diffi- 
culties which were experienced arose from this cable ; the strain of the 
wind and the waves was constantly damaging it, and as the Blioda 
swung round with the wind great care was necessary to prevent the 
cable fouling with the anchor chain. On the Rlioda there were three 
large drums, op which there were wound the leads for the resistance 
thermometers. By these drums a thermometer could be lowered to any 
desired depth, and then connected to the shore-cable by means of 
mercury cup connections, and a continuous record of the temperature 
at that depth could thus be obtained. It was intended to lower each 
of the three thermometers to a different depth, and connect them 
successively with the recorder, and so to get a series of readings at 
these depths, but the sluggishness of the recorder made this method 
of observation undesirable. 
Temperature observations were taken at various points along Loch 
Ness. At times members of the survey were stationed at Invermoriston, 
Foyers, Inverfarigaig, Whitefield, and Dores. At other times a steam 
launch was chartered, and cruises made up and down the loch, taking 
observations en route, but this method of observation was very slow. 
The speed of the launch was about six miles an hour, and, as the loch is 
24 miles in length, about eight hours were spent in steaming alone ; 
assuming that six series of observations were taken, each lasting over 
half an hour, the observations at one end of the loch were taken six 
or seven hours later than at the other end. It was found that in this 
time the distribution of temperature in the loch might alter very 
greatly, and therefore observations made in this manner might give a 
very erroneous idea of that distribution. 
The observations in Loch Ness were discontinued by members of the 
Lake Survey in September, 1904, but the work was taken over by the 
monks at Fort Augustus (in particular by Father Cyril von Dieckhoff 
and Father Odo Blundell), and continued by them until April, 1905, 
so that the observations extend over a period of nearly two years. The 
actual number of observations made in that time was about 12,000, 
and these have been discussed by the writer in papers communicated 
DD 
