250 
HINTS TO TRAVELLERS, 
TABLE VII.—( continued ). 
Mean Astronomical Refraction. 
(Barom. 30 inches ; Therm. 50° Fahr.) 
App. 
Alt. 
Refr. 
App. 
Alt. 
Refr. 
App. 
Alt. 
Refr. 
0 / 
t n 
0 1 
/ n 
0 t 
/ n 
15 50 
3 23 
31 00 
1 37 
57 00 
O 37-9 
16 00 
3 21 
31 30 
1 35 
58 co 
O 36*5 
16 10 
3 19 
32 CO 
1 33 
59 00 
0 35*i 
16 20 
3 17 
32 30 
1 31 
60 00 
0 33 * 7 
16 30 
3 15 
33 00 
1 30 
61 00 
0 32-4 
16 40 
3 13 
33 30 
1 28 
62 00 
0 31*0 
36 50 
3 11 
34 00 
1 26 
63 co 
0 29*8 
17 00 
3 09 
34 30 
1 25 
64 CO 
0 28-5 
17 30 
3 oj 
35 00 
1 23’2 
65 00 
0 27-2 
18 00 
2 58 
35 30 
1 21*7 
66 00 
0 26*0 
18 30 
2 53 
36 00 
I 20*2 
67 00 
0 24*8 
19 00 
2 48 
36 30 
i 18-8 
68 00 
0 23*6 
19 30 
2 44 
37 °° 
1 17-4 
69 co 
O 22*4 
20 OO 
2 39 
37 30 
1 i6'o 
70 00 
O 21*3 
20 30 
2 35 
38 00 
1 14*6 
71 00 
O 20* I 
21 00 
2 31 
38 30 
1 13*3 
72 00 
O 19*0 
21 30 
2 27 
39 00 
I 12*0 
73 co 
O 17*9 
22 OO 
2 24 
39 30 
i 10*7 
74 00 
0 i6’7 
22 30 
2 20 
40 CO 
1 09-5 
75 co 
0 15-7 
23 OO 
2 17 
41 00 
1 07*1 
76 00 
0 14*6 
23 30 
2 13 
42 00 
1 04-8 
77 00 
0 13-5 
24 OO 
2 IO 
43 CO 
I 02-6 
78 00 
O 12*4 
24 30 
2 07 
44 00 
,1 00-4 
79 00 
0 n *3 
25 OO 
2 05 
45 00 
0 58*4 
80 00 
0 10*3 
25 30 
2 02 
46 00 
0 5^-3 
81 00 
0 09*2 
26 OO 
i 59 
47 00 
0 54*4 
82 00 
0 o8'2 
26 30 
1 56 
48 CO 
0 52-6 
83 00 
0 07*2 
27 OO 
1 54 
49 00 
0 50-7 
84 00 
0 06 • I 
27 30 
1 5 i 
50 00 
0 49*0 
8, 00 
0 05*1 
28 OO 
1 49 
51 00 
0 47*3 
86 00 
0 04*1 
28 30 
1 47 
52 00 
0 45-6 
87 00 
0 03*1 
29 OO 
1 45 
53 00 
0 44 *o 
88 00 
O 02*0 
29 30 
1 43 
54 00 
0 42*4 
89 00 
0 OI'O 
30 OO 
30 30 
1 4 i 
1 39 
55 00 
56 00 
0 4°‘9 
0 39*4 
90 co 
0 00*0 
Corrections when Barom. 
differs from 30 inches or 
Therm, from 50° Fahr. 
App. 
Alt. 
25 
30 
35 
40 
45 
50 
55 
60 
65 
25 
30 
35 
40 
45 
50 
55 
60 
65 
Barometer. 
For each inch above or 
below 30 inches:— add, 
if above 30 ; subtract , if 
below. 
Thermometer. 
App. For each 10 degrees above or 
Alt. below 50° Fahr. sub¬ 
tract, if above 50°; add , 
; if below. 
