Nichols.] 
56 
[October 6, 
Table II. Observations on Mystic Lake. 
[Temperatures expressed in centigrade degrees.] 
Date. 
Daily Mean Tem- 
perature 
at Boston. 
Temperature of air 
at time 
of observation. 
Temperature in 
Pump-well 
of Water- works. 
2 feet from surface. 
18 — 20 ft. fm. surfe. 
36 feet fr. surface. 
50 — 55 feet from 
surface. 
70 — 75 feet from 
surface. 
Approx, depth at 
point of observat’n. 
Height of water in 
Lake in gate house 
in feet. 1 
October 18, 1879, 
16.8 
19.0 
16.7 
16.5 
16.3 
6.8 3 
___ 
6.8 
72 
2.24 
November 5, 
—2.8 
5.3 
8.1 
7.8 
7.9 
— 
— 
6 . 0 2 
65 
1.35 
U 
8, 
9.4 
— 
7.2 
7.3 
7.3 
— 
6.8 
— 
55 
1.30 
u 
15, 
18.3 
18.3 
8.3 
9.5 
8.8 
— 

6. 8 2 
65 
1.13 
It 
22, 
—4.6 
—0.2 
6.1 
6.7 
6.3 
— 
6.0 
— 
55 
1.07 
December 
8, 
5.7 
6.4 
5.0 
4.9 
4.9 
— 
— 
4.9 
75 
0.87 
a 
12, 
0.9 
2.4 
5.0 
4.9 
5.2 

— 
5.0 
75 
0.95 
u 
19, 
—3.3 
1.6 
3.6 
3.0 
3.7 
— 
_ 
3.9 
80 
1.71 
a 
23, 3 
—1.8 
— 
1.4 
— 
— 
— 
— 
— 
— 
1.67 
January 30, 1880, 6 
1.5 
— 
2.5 
2.5 
2.8 
— 
— 
2.8 
75 
6.22 
February 
6,6 
—2.1 
— 
1.7 
1.2 
2.6 
— 
— 
3.2 
75 
6.31 
a 
17,6 
6.7 
— 
1.4 
0.9 
2.8 
— 
. 
3.0 
75 
6.20 
u 
18,7 
11.9 
11.0 
1.4 
1.9 
2.8 
— 
— 
3.1 
75 
6.10 
u 
44 
11.9 
11.0 
1.4 
2.4 4 
2.8 
2. 8 3 
— 
2. 8 2 
64 
6.10 
u 
44 
11.9 
11.0 
1.4 
— 
2.8 
2. 8 3 
— 
— 
42 
6.10 
Cl 
u 
11.9 
11.0 
1.4 
2. 1 4 
— 
— 
— 
— 
30 
6.10 
u 
27, 8 
9.0 
5.6 
2.2 
2.4 
— 
— 
— 
— 
— 
6.03 
March 
2,9 
0.7 
2.0 
2.5 
2.6 
— 
3.0 
— 
— 
40 
6.15 
a 
6, 
0.8 
6.4 
3.3 
4.1 
4.0 

— 
4.0 
75 
6.16 
it 
10,12 
—1.4 
0.2 
3.0 
3.4 
3.6 
— 
— 
3.8 
75 
5.99 
u 
13, 
—4.7 
—4.5 
2.5 
2.9 
3.0 
— 
_ 
3.2 
75 
5.96 
a 
24,13 
—2.1 
8.4 
3.3 
3.6 
3.6 
— 
— 
3-7 2 
68 
6.08 
u 
27, 
—0.6 
3.6 
2.5 
2.9 
3.0 

— 
3.2 
75 
5.82 
April 
5, 
11.4 
9.4 
4.6 
4.8 
4.8 
— 
— 
4.9 
75 
6.28 
u 
13, 
10.7 
15-0 
5.6 
6.3 
6.2 
— 

6.1 
75 
5.88 
«C 
14, 
5.7 
13.9 
6.1 
7.2 
6.6 
— 
— 
6.1 
75 
5.95 
u 
17, 
2.3 
5.3 
7.2 
7.2 
7.2 
— 
— 
6.2 
75 
5.26 
May 
3 , 
18.3 
25.0 
10.0 
10.9 
10.7 
— 
— 
6.7 
75 
6.52 
U 
12, 
16.2 
21.1 
17.8 
18.5 
12.8 
— 
— 
6.7 
75 
6.26 
44 
15, 
11.5 
15.6 
15.6 
16.1 
14.8 
9.6 
7.4 
6.8 
75 
6.25 
44 
24, 
24.6 
30.0 
18.9 
21.0 
15.9 
— 
— 
6.9 
75 
6.20 
June 
3 , 
14.3 
— 
20.3 
20.9 
19.0 
9.2 
7.4 
6.9 
75 
5.53 
44 
18, 
19.7 
— 
22.8 
22.7 
18.2 
— 
— 
7.2 
75 
4.64 
« 
25, 
25.3 
— 
23.1 
24.3 
19.2 
— 
— 
8.3 
75 
3.97 
1 High water is 7.00. 
2 At 60 — 65 feet from surface. 
3 At 40 feet from surface. 
4 At 6 feet from surface. 
5 Ice formed on the night of Dec. 22-23. 
6 Pond covered with ice. 
7 Ice melting rapidly. 
8 Pond about one- quarter open. Obser- 
vation made at gate-house. 
9 Ice broke up March 1 ; much drift ice 
at date. 
12 Thin ice at edges of pond. 
13 Thin ice formed last night; all gone at 
10 A.M. 
