Part III. — Eleventh, Annvnf fr&jpbfct 



afternoon, showing a marked cvccss in the Inhii&l average temperature of 

 febe water at 8 p.m. bdthpistrsea with 9 a.m. This mean is six-tenths of a 

 degree bblb'w the mean temperature in 1891, both at 9 a.m. and 3 p.m., 

 and consequently fully a degree lower than that of 1890. 



The maximum monthly means were 12°-8 at 9 a.m. and 1 3°'l at 3 p.m. 

 in August, and the minima were 5°-5 and 5°-7 — a range of 7°'3 and 

 7°'4. This is half a degree greater range than that of 1891, the minima 

 being three-tenths lower, and the maxima two-tenths and one-tenth higher 

 than in the previous year. 



Nor are the extremes so far apart, for the maximum reading was 14 0, 6 

 on August 1 and again on August 24, and the minimum 4° "2 on the fore- 

 noons of February 19 and 20 — a range of 10 o, 4. While the mean monthly 

 range is greater, that of the extremes of temperature is eight-tenths of a 

 degree less than that of the previous year. 



The curve of surface temperature is fairly regular, showing arrests both 

 in rise and in fall. The highest point was reached in the last ten-day period 

 of June, but there was a second and not much lower maximum at the end 

 of August. 



The mean surface temperature for the year coincides with that of the 

 last period of May, and with that of the middle of November, much later 

 dates than those for the surface temperatures of other stations. 



Wed Loch Tarberi. 



Very regular observations have been taken, but only at 3 p.m. 



The mean annual temperature of the surface water was 9°*4, and 

 that of the bottom water, which varies in depth from 2 to 4J fathoms, 

 was also 9° '4. This is 0 o, 5 lower than mean surface temperature, and 

 0 o, 4 lower than mean bottom temperature for 1891. 



The highest monthly mean was that of August (surface, 15 0, 4; bottom, 

 15° -3), and the lowest that of January, when the mean surface tempera- 

 ture was 4°'l, and the mean bottom temperature 4°*3. The range 

 of mean surface temperatures is thus 11 0, 3, and that of bottom 11° -0. 

 The highest monthly mean is fully three-quarters of a degree below that 

 of 1891, and the lowest is from one- to three-tenths higher. 



The highest readings during the year were 17°"0, recorded on August 

 2 and 23 at the surface, and 16° '6 obtained on the former date at the 

 bottom. The minima were 2°*2, observed on March 3 and 10 at the 

 surface, and on March 3 at the bottom. The extremes are thus 14° '8 and 

 14°-4, compared with 15°-2 and U°r% in 1891. 



Thp curves of the water temperatures follow those of the air very closely, 

 showing a marked break in the regular rise corresponding to colder 

 periods at the beginning of June and of July; the rise of temperature 

 at the end of October and the beginning of November is well marked, and 

 after a sharp fall of about 3° in the last two ten day periods of November 

 the falling curve turns upwards in sympathy with a rise of the air tem- 

 perature in the first period of December. 



There is comparatively little difference between the surface and bottom 

 temperatures, the former being one or two tenths of a degree higher in 

 summer and lower in winter. 



The line of mean temperature was reached about the same period in the 

 springs of 1891 and 1892, but somewhat earlier in the autumn of 1892 

 than in that of 1891. In 1892 the air was at its mean temperature at the 

 end of April and in the second week of October : the surface water was 

 a day or two later in reaching the mean, and the bottom water still a day 

 or two later. In both years a temporary rise of air temperature took place 

 in autumn, but about a fortnight earlier in 1891 than in 1892. 



