38 TRANSACTIONS — PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
TEMPERATURE. 
Another department in which observations are still much needed 
is the important one of temperature. Any observations which have 
yet been taken, although correct and useful so far as they go, are too 
meagre, and extend over too short a period to be of service for 
generalising purposes. Observations were taken at Perth by Messrs. 
W. Wilson, R. Dow, and A. M. Mechie, from December, 1887, to May, 
1888; and at Inver, near Dunkeld, by Messrs. C. and J. Macintosh, 
from March, 1889, to June, 1890. The results of these investiga¬ 
tions are published in the “ Fourth Report of the Committee on 
Seasonal Variation of Temperature in Lakes, Rivers, and Estuaries,” 
drawn up for the British Association Meeting at Cardiff in 1891. 
In the Perth observations the monthly mean of the temperature of 
the Tay varied from 35'9 deg. in December to 46’9 in May. At 
Inver the lowest monthly mean was 37'8 in February, 1890; the 
highest was 607 in July, 1889. The full tabulated results are here 
reproduced from the Report:— 
JMonthly Means of Temperature Ohsej'vations on the Tay at Perth, g a.m. 
Month 
Year 
Air 
Water 
Weather 
December 
1887 
0 
327 
0 
35-9 
Some snow and frost. | 
T anuary 
1888 
40’O 
37-8 
Some fog and rain. j 
February 
> ) 
367 
37-5 
W. and N.F. winds; some snow, j 
March . 
9 ? 
37-9 
37-4 
W. winds; some snow. j 
April 
39 
45-8 
43‘6 
N, winds; some rain. 1 
May 
3 3 
50 '3 
46-9 
N. and W. winds. j 
JMonthly Means of Temperature Observations on the Tay at Inver, 
7 iear Dunkeld. 
iMonth 
Year 
Air 
Water 
Weather and General Direction of Winds. 
iMarch . 
1889 
0 
41 ’2 
39-8 
N.W. wind; changeable; some thunder. 
April 
9 3 
42'O 
417 
N.W. wind; stormy; some snow. 
jNIay 
3 » 
50-8 
507 
E. winds; fine; dull; showers. 
June 
9 3 
557 
57’o 
N.W. and E. winds. 
July 
9 3 
56-2 
607 
No remarks. 
August . 
3 3 
53-5 
557 
9 3 
September 
3 3 
507 
53’4 
3 9 
October . 
9 3 
43'2 
46’ I 
9 9 
November 
9 3 
407 
43‘o 
9 3 
December 
» 9 
1890 
37-9 
397 
9 3 
January . 
36*6 
397 
9 9 
February 
3 9 
347 
37'8 
s y 
March . 
9 9 
42'6 
397 
9 9 
April 
9 3 
417 
437 
' 3 ! 
May 
9 9 
49'2 
507 
9 9 
June 
9 3 
557 
53'4 
9 9 
