182 
METEOROLOGICAL REPORT. 
Sydney, Month of December, 1857- 
From observations taken at 9 a.m. and 9 p-m. each da?/. 
I 
Barometer, Re¬ 
duced &c. 
Temperature of Air. 
Moisture 
o 
S’ 
p 
be 
P 
P 
m 
Cloud, 
Winds. 
Remarks 
on 
Weather, etc. 
‘‘o ■ g 
c S s. 
P 
P 
s 
M 
S 
Minimum. 
Range. 
Daw point. 
Rain. 
Inches. 
1 Extent. 
Form. 
Gene ral 
Direction 
1 
30030 
69'2 
76-4 
58-8 
17-6 
57-2 
•00 
1 
| Cu. 
NNE. 
Fresh breezes and fine. 
2 
29-824 
69-3 
79-4 
53-8 
25-6 
59-4 
•53 
6 
Ci.-St. Ni. 
South 
Thunderstorm. 
3 
•904 
59-7 
66-2 
56-3 
99 
54-8 
•07 
10 
10 
! Ni. 
SSE. 
"J Strong winds and 
4 
30-036 
62 T 
66-G 
57 0 
0-6 
572 
*05 
25 
8 
f Cu. Ni. 
SE. 
> large black 
5 
•226 
64-2 
71-5 
56-0 
15-5 
54-0 
■00 
100 
3 
Cu. Cu.-St 
SE. 
J clouds. 
68 
•192 
69-2 
76 9 
49-3 
27-6 
57-3 
•00 
149 
O 
Cu. 
NS. 
1 Very fine. Fresh 
■143 
70-6 
77-6 
505 
271 
59-8 
.00 
134 
0 
NE. 
[ sea breezes. 
8 
29-926 
72*2 
81 2 
610 
20-2 
62-5 
•00 
134 
0 
Ci.-St. 
NNE. S. 
Sultry. 
9 
•992 
G9-5 
71-8 
61-0 
108 
034 
•28 
72:10 
Cu -Ni. 
S. NE. 
9th. Remarkable thun- 
10 
30-022 
70-5 
75-8 
6-31 
12-7 
65-9 
■00 
120 
4 
Cu. 
SE. 
derstorm. 
11 
29-894 
73-8 
811 
63 6 
17-5 
65-2 
00 
134 
5 
Ci.-St 
NNE 
Sultrv. 
12 
•832 
74-3 
90-2 
047 
25-5 
670 
•00 
8940 
Ci.-St 
NE. S. 
“ Southerly ” at 9 p.m. 
13S 
30 094 
63'(5 
70S 
583 
12-5 
553 
•09 
38! 
6 
Cu 
SSE. 
Thunder-shower 
14 
•228 
65-7 
72-2 
580 
14-2 
50-3 
■07 
51 1 
6 
Cu.-St 
SSE 
Dark clouds. 
15 
•190 
69 '9 
810 
58-3 
22-7 
63-0 
•05 
121 
3 
Cu. 
E. NE 
Agreeable weather. 
16 
•0S2 
70-9 
79-1 
64-0 
lo’4 
02-2 
•00 
78 
0 
Ci.-St. 
NH. 
3keet-Iightning. 
17 
29-933 
70-3 
80-8 
GO-3 
20-5 
oo-i 
•00 
6 
Ci.-St. Ni. 
SW. Var. 
rhunder clouds. 
18 
•878 
75-0 
810 
54-3 
29-7 
03-8 
•00 
70 
0 
Cu. 1 
NE. 
Fine. 
19 
•795 
730 
81-3 
GIG 
20-2 
050 
•00 
139 
0 
NE. 
Sheet-lightning. 
20S 
•860 
70-2 
783 
G2-3 
16-0 
02-6 
•00 
53 
8 
Cu. 
South 
| Fine but 
21 
•987 
72*0 
81-2 
61-6 
19-fi 
62-8 
•00 
121 
0 
Cu. 
NE. 
>• cloud v 
22 
30-045 
72-9 
82.2 
64-4 
17-8 
651 
•00 
104 
10 
Cu. 
NE. 
j weather. 
23 
29 8S9 
76-7 
84-3 
69-0 
24-3 
G7‘5 
•00 
138 
1 
NE. 
Strong breeze. 
24 
•921 
81-2 
108-0 
630 
450 
55-0 
•00 
116 
3 
Cu. 
NW. S. 
Extreme hot-wind 
25 
30213 
64-6 
63-8 
62-3 
6-5 
57-4 
•00 
8 
10 
Cu. 
SSE. 
Black clouds. 
26 
29-975 
72-S 
80-8 
48-3 
32-5 
620 
•00 
110 
4 
Ci.-St. 
NNE. 
Fine. 
27S 
•852 
G9-5 
83-5 
59 0 
24-5 
617 
•00 
43 
9 
SSE 
Much cloud. 
28 
•846 
70-4 
79-3 
59-3 
20-0 
60-2 
•00 
83 
5 
Cu. 
North, 
Clearing. 
29 
•763 
69-2 
73-3 
64-4 
S-9 
590 
•00 
10 
10 
Cu. 
SW. SSE. 
Southerly squalls. 
so 
30-013 
65'2 
71-5 
59-3 
12-2 
55'2 
•00 
17 
9 
Cu. 
SSE 
1 Dark clouds, clear- 
31 
•071 
64-2 
720 
50-8 
21-2 
5S-0 
•12 
22 
0 
Cu.-Ni. 
NE. 
j ing at nights. 
30-237 
950 
108 0 
59-7 
70-0 
•53 
10 
Hi 
ghest ) of single readings. 
29-600 
59-2 
48-3 
51-2 
0 
Lowest J at 9 a.m. or 9 p.m. 
29-991 
69-7 
78-3 
58-9 
104 
CO-5 
1-26 
86 
'55 
Means and sums. 
December, 1857. 
1 57 0 
29 935 
66-6 
76-0 
| 19-0 
58-0 
| 4-11 
... 
•65 
N.B.—The observations are not corrected for diurnal 
range The principal instruments have been compared 
at Greenwich, and the readings are all reduced ac¬ 
cordingly. 
Pressure .—The barometer is 11 feet, above the sea-level 
the greatest range of pressure is *037 inch. The 
mean gaseous pressure of dry air is 29'463 inches. 
The average weight of a cubic foot of air is 523 grs. 
The reading of the barometer has, on the whole, 
been very fluctuating this month. 
Temperature of Air ,—The mean of all self-registered 
maxima and minima is 68 6 degrees. The adopted 
mean temperature of the month is, therefore, 69’1 
degrees. The adopted mean temperature ol the month 
for the two previous years is 66*5 degrees. 
Moisture .—The dew-point is calculated from readings of 
Negretti’s and Zambia’s dry and wet bulb thermome¬ 
ters, by the use of Glaisher’s tables. 2nd Edn. 
The mean temperature of evaporation at 9 a.m. and 
9 p.m, is 64'5 degrees. The mean elastic force of 
vapour is *528 inch. The average proportional 
humidity of the air is denoted by 73, perfectly dry 
air being taken as 0, and saturated damp air as 100. 
Ram .—More or less rain fell on S days during the 
month. The total depth being 1*26 inches. It is 
collected at one foot above the ground, and measured 
at 9 p.m. 
Evaporation *—The total depth of water evaporated with 
full exposure to sun and wind is 6'03 inche s 
Omitting four davs. 
Sunshine .—'The numbers in the eleventh column denote 
roughly the proportional total amounts of sun’s 
heat fallen during each day, as measured by the 
sun-gauge described in the Sydney Magazine for 
August. . ^ , 
Clotid. —Tl\e extent of cloud is expressed by the tenths 
of the whole sky covered by it. 
The forms of clouds are denoted as follows, the num¬ 
ber of days on which each kind occurred dunng 
the month being added in figures. 
Cumulus 20 “ Ci-Cu. ^Cirro-cumulus. ... 0 
Cirrus.0 Ci.-St. Cirro-stratus . 7 
Stratus.1 Ou.-St. Cnmulo-stratus .i. 1 
Ni Nimbus,...6. 
Winds .—The winds may btf thus summed up. 
Cu. 
Ci. 
St. 
NW. 
SW 
South 
Yar. 
1 day 
l- 
4 
I f 
North 
SSE 
SE 
East 
64 davs. 
3 „ 
4 » 
N E 10£ 
NN E 3£ 
1 day. 
The temperature of this month was, on an average, 
nearly three degrees above that of the same month 
for the last two years. ___r A>T n 
W. S. JEYONS. 
Double Bay, near Sydney, N.S.W. 
