218 
HINTS TO TEAVELLEKS, 
PART II. 
Correction due to T—T', or the Difference of the Temperatures of the Barometers themselves 
(not for that of the intermediate air) at the two Stations. 
This Correction is Negative when the Temperature at the upper station is lowest , and vice versa. 
T—T'. 
Correction. 
T—T'. 
Correction. 
T—T'. Correction. 
T—T'. 
Correction. 
T—T'. 
Correction. 
T—T'. 
Correction. 
Fahr. 
Feet. 
Fahr. 
Feet. 
Fahr. 
Feet. 
Fahr. 
Feet. 
Fahr. 
Feet. 
Fahr. 
Feet. 
0 
1 
2 3 
0 
14 
32*8 
0 
27 
63*2 
0 
40 
9**6 
0 
53 
124* 1 
6°6 
154*5 
2 
4*7 
15 
35*1 
28 
6r5 
4i 
96*0 
54 
120*4 
67 
156*8 
3 
7-0 
16 
37*5 
29 
67-9 
42 
98*3 
55 
128*7 
68 
159*2 
4 
9’4 
17 
39*8 
30 
70*2 
43 
100*7 
56 
131*1 
69 
161*5 
5 
n*7 
18 
42*1 
3i 
72*6 
44 
103*0 
57 
133*4 
70 
163*9 
6 
14*0 
19 
44*5 
46*8 
32 
74*9 
105*3 
58 
135*8 
7i 
166 *2 
7 
i6*4 
20 
33 
77 *3 
46 
107*7 
I 9 
138*1 
72 
168*6 
8 
18-7 
21 
49*2 
34 
79*6 
47 
110*0 
60 
140*4 
73 
170*9 
9 
21*1 
22 
5i*5 
35 
81-9 
48 
112*4 
61 
142*8 
74 
173*3 
10 
23-4 
23 
53*8 
36 
84*3 
49 
n 4 *7 
62 
145*1 
75 
175*6 
11 
25*8 
24 
56*2 
37 
86*6 
50 
117*0 
63 
147*5 
76 
177*9 
12 
28*1 
25 
58*5 
38 
89*0 
5i 
119*4 
64 
149*8 
77 
180*3 
13 
30*4 
26 
60*9 
39 
91-3 
52 
121*7 
65 
152*2 
78 
182*6 
PART III. 
Correction due to the Change of 
Gravity from the Latitude of 
45 0 to the Latitude of the Place 
of Observation. 
Positive from Lat. o° to 45 °; 
Negative from Lat. 45 0 to 90 °. 
• 
Latitude. 
App. 
o° 
10 ° 
20 ° 
30 ° 
4 °° 
45 ° 
Alt. 
90 0 
8 o° 
70 ° 
6 o c 
50 ° 
Feet. 
Feet. 
Feet. 
Feet. 
Feet. 
Feet. 
Feet. 
1000 
2*6 
2*5 
2*0 
i *3 
0*5 
o 
2000 
5*3 
5 *o 
4 *i 
2*6 
0*9 
o 
3000 
7*9 
7*5 
6 *i 
4*0 
i *4 
0 
4000 
io *6 
10*0 
8 *i 
5*3 
i *8 
0 
5000 
13*2 
12*4 
10*1 
6*6 
2*3 
0 
6000 
15*9 
14*9 
12*2 
7*9 
2*8 
0 
7000 
18*5 
17*4 
x 4 * 2 
9*3 
3*2 
0 
8000 
21*2 
i 9*9 
16*2 
io *6 
3*7 
0 
9000 
23*8 
22*4 
i 8*3 
n *9 
4 * x 
0 
10000 
26*5 
24*9 
20*3 
13*2 
4*6 
0 
11000 
29*1 
27*4 
22*3 
14*6 
5*1 
0 
12000 
31*8 
29*9 
24*4 
15*9 
5*5 
0 
13000 
34*4 
32*4 
26*4 
17*2 
6 *o 
0 
14000 
37 *i 
34*9 
28*4 
18*5 
6*4 
0 
15000 
39*7 
37*3 
30*4 
19*9 
6*9 
0 
16000 
42-4 
39*8 
3 2*5 
21*2 
7*4 
0 
17000 
45 *o 
42*3 
34*5 
22*5 
7*8 
O ! 
18000 
47*7 
44*8 
36*5 
23*8 
8*3 
O 
19000 
50*3 
47*3 
38*6 
25*2 
8*7 
O 
20000 
53 *o 
49*8 
40*6 
26*5 
9*2 
O ! 
21000 
55*6 
52*3 
42*6 
27*8 
9*7 
O 
22000 
58*3 
54*8 
44*7 
46*7 
29*1 
10*1 
O 
23000 
6 °*o 
57 *3 
30*5 
io *6 
O 
24000 
63*6 
59*8 
48*7 
31*8 
11*0 
O 1 
25000 
66*2 
62*2 
5 o *7 
33*1 
ii *5 
O 
PART V. 
: Correction due to the Height of the 
Lower Station. 
Always Positive. 
Height of Barometer at Lower Station. 
App. 
16 in. 
18 in. 
20 in. 
22 in. 
24 in. 
26 in. 
28 in. 
Alt. 
Feet. 
Feet. 
Feet. 
I Feet. 
Feet. 
Feet. 
Feet. 
Feet. 
i*6 
i *3 
1*0 
! o*8 
o*6 
0*4 
0*2 
1000 
3 *i 
2*5 
2*0 
i *5 
i*i 
0*7 
o *3 
2000 
4*7 
3*8 
3 *o 
2*3 
i *7 
i*i 
o *5 
1000 
6*3 
5 *i 
4*0 
3*1 
2*2 
i *4 
0*7 
4000 
7*8 
6 *4 
5 *o 
3*8 
2*8 
1*8 
o*8 
50CO 
9*4 
7*6 
6*o 
4*6 
3*3 
2*1 
I *0 
6000 
11*0 
8*9 
7 *i 
5*4 
3*9 
2*5 
1*2 
7000 
12*5 
10*2 
8*1 
6*2 
4*4 
2*8 
1*3 
8000 
14*1 
n *4 
9 *i 
6*9 
5*0 
3*2 
i *5 
9000 
15*7 
12*7 
10*1 
7*7 
5*5 
3*5 
i *7 
10000 
17*2 
14*0 
ii*i 
8*5 
6*i 
3*9 
i*8 
irooo 
18 * 8 
15*3 
12*1 
9*2 
6*6 
4 *? 
2*0 
12000 
204 
16*5 
13*1 
10*0 
7*2 
4*6 
2*2 
13000 
21*9 
17*8 
14*1 
io*8 
7.7 
4*9 
2*3 
14000 
23*5 
191 
15*1 
ii*5 
8*3 
5*3 
2-5 
15000 
25*1 
20*3 
16*1 
12*3 
8*8 
5*6 
2*7 
16000 
26*6 
21*6 
17*1 
13*1 
9*4 
6*o 
2*8 
17000 
28*2 
22*9 
18*1 
13*8 
9*9 
6*3 
3 *o 
18000 
29*8 
24*1 
19*2 
14*6 
io*5 
6*7 
3*2 
19000 
3 i *3 
25*4 
20*2 
15*4 
11*0 
7*0 
3*3 
2ocoo 
3 2*9 
26*7 
21*2 
i6*i 
11 *6 
7*4 
3*5 
21000 
34*5 
28*0 
22*2 
16*9 
12*1 
7*7 
3 ‘ 7 
22000 
36*0 
29*2 
23*2 
17*7 
12*7 
8*i 
3*8 
23000 
37*6 
30*5 
24*2 
i 8*5 
13*2 
S ’ 4 
4*0 
24000 
39 * x 
31*8 
25*2 
19*2 
13*8 
8*8 
4 * x 
25000 
PART 
IV. 
De¬ 
crease 
on A 
Verti¬ 
cal. 
Always 
Feet. 
2*5 
5-2 
7*9 
io*8 
*n 
16*7 
x 9*9 
23*1 
26-4 
29*8 
33*3 
3 6’9 
40*6 
44*4 
48 3 
52 3 
56-4 
60*5 
64-8 
69*2 
73*6 
78-2 
82*9 
87-6 
92 *5 
