TABLE VIII.

PARALLAX OF THE SUN ON THE FIRST DAY OF EACH MONTH, THE MEAN HORIZONTAL PARALLAX BEING 8" 60.

The Sun's Horizontal Parallax is also given for every ten days, in the Nautical

nac, immediately before the ephemeris of the planets.

The Sun's Parallax in Altitude, for every degree, is given in the last of Dr. Pea "Solar Tables," vol. i. page 180.

TABLE IX.

REDUCTION OF THE MOON'S EQUATORIAL HORIZONTAL PARALLAX, TO THE HORIZONTAL PARALLAX IN ANY LATITUDE.

The Moon's Horizontal Parallax, given in the third page of each month in the Nautical Almanac for noon and midnight, is the equatorial parallax for Greenwich mean noon and midnight; from thence it is to be deduced for the time and place of observation. The correction for latitude, on account of the spherical figure of the earth, is seldom thought of at sea, but can be made from the table above. Thus, supposing the hor. equat. par. to be 58'; the hor. par. in lat. 52° would be 58′ 7′′-2 = 57′ 52"-8.

This reduced hor. par. is to be farther corrected for altitude by means of tables for that purpose (see Pearson, vol. i. pages 188 to 196: and Riddle, pages 156* to 173); or by the following rule:-sin hor. par. X cos alt. sine par. in alt.

=

* Riddle's tables are for clearing the lunar distance, and the corrections are for both parallax and refraction.

The Parallaxes and Semidiameters of the Planets are given in the Nautical Almanac.

DIP OF THE SEA HORIZON AT DIFFERENT DISTANCES FROM IT.

75.5

101.8 132 0

166-2

204.2

759

102-3 132.6

1668

2049

76.3

17 0-2 3-2 18 0-2 33

10.2

20.7 35.5 54'1
20.9 35'7 54.5
21.2 36'0 54.8

76.7

77.1

77:5

36.3 55.1

21.6

36.6 55.5 78.3

1051

292-2 342'0 395-8 2470 2930 342-9 396-7 102-7 1331 167 4 2056 2477 293-8 343.7 397-6 103.2 133'6 1680 206-3 248-5 294'6 344-6 398*6 103-7 134-2168-6 2069 249-2 295 4 345-5 399.5 104.2 134-7 169.2 2076 249′9 169-8 208 3 250-7 135-8 170-4 2089 251-4 297-8 3481 402-3 105 6 136 3 171-0 2096 252.2 298-6 349-0 403.3 1061 136'9 171-6 2103 253'0 299-4 349-8 404-2 1066 137 4 172-2 2110 253'6 300 2 350.7 405.1 1070 1380 172.9 2117 254:4 107.5 138.5 173-5 212-3 2551 1080 1391174-1 2130 2559 108.5 139'6 174-7 213-7 2566 81.7 1090 140 2 175.3 2144 257-4 1095 1407 175.9 2151

24.0 39'8

110-4 141-8 177-2 2164

1109 1424 177-8 2171
1114 1430 178-4 217-8 2611
111.9 143-5 179-0 218-5 261-9
112-4 1441 179-7 219-2 262-6 3100 361 3 416-5
112.9 1446 180-3 219-9 263-4 3108 3622 417.5
113-4 145 2 180-9 2206 264.1 3116 363 1 418-4
113.9 1458 1816 221-3 264.9 312-5 364.0 419.3
114.4 1463 182-2 2220 265-7 313.3 364-8 420-3
1149 1469 182.8 222-7 266-4 3141 3657 421-3
115 4 147-5 183.5 223-4 267-2 3150 366'6 422.2
115'9 148'0 184.1 224.1 267-9 315'8 367-5 423-2
116 4 148-6 184-7 224-8 268-7 3166 368 4 424.2
116.9 149-2 185-4 225.5 269-5 317-4 369-3 425.1

19 0-2 34 10-5
20 0.2 3.5 10.7
21 0.2 36 10-8
22 03 37 11.0
23 0.3 3.8 11.2
24 0.3 38 11.3
25 0.3 3.9 11:5
26 0-4 4-0 11.6
27 0.4 4.1 11.8
28 0.4 4.2 11.9
29 0.5 43 12.1
30 0.5 44 12.3
31 0.5 45 12:4 24.3 40'1 59'8 83.4
32 0.6 46 12.6 24.5 40'3 60'1 83.8
33 0.6 4.7 12.8 24.7
40'6 60'5 84.2
34 0-6 4-8 12.9 25.0 40'9 60'8 84.7
35 0.7 4.9 13.1 25.2 41'2 61.2 85.1
36 0.7 5.0 13:3 25.4 '41'5 61.6 85.5
37 0.7 5.1 13:4 25.7 41'8 61.9 86'0
38 0.8 5.2 13.6 25.9 42'1 62'3 86.4
39 08 5.3 13.8 26.2 42'5 62.7 86.8
40 0-9 54 14:0 26.4 42'8 63'0 87.3
41 0.9 5.6 14.1
26.6 43'1 63'4 87.7
42 1.0 5.7 14:3 26.9 434 63.8 88.1
43 1.0 5.8 14:5 27.1 43'7 64.2
88.6
44 1.1 5.9 14.7 27.4 44'0 64.5
89.0 117-4 149-7186'0 226-2 270-3 318-3 370-2 426.1
45 1.1 60 14.8 27.6 44°3 64.9 89.5 117.9 150-3 1866 226-9 271-0 319-1 371-1 427.0
46 1.2 6.1 15.0
27.9 44'6 65.3 89.9 1184 1509 187-3 227-6 271-8 319.9 372.0 428.0
47 1.2 6.2 15.2
28.1 44'9 65'7 90.3
118.9 151.5 1879 228-3 272.6 3208 372-9 429-0
48 1.3 64 15:4 28.3 45'2 66'0 90.8 119.5 152-0 188.5 229.0 273.3 3216 373-8 429.9
49 1.3 65 15.6 28.6 45'5 66'4 91.2 1200 152-6 189.2 229.7 274-1 322-4 374-7 430-9
50 1.4 6.6 15.8 28.8 45'9 66'8 91.7 120.5 153.2 189-8 230-4 274.9 323-3 375-6 431-9
51 14 67 15.9 29.1 46'2 67°2 92.1 1210 153.8 190-5 231-1 275 6 324°1 376-5 432.8
52 1.5 6.8 16.1 29.4 46'5 67'6 92.6 121.5 154 4 191-1 231.8 276 4 325 0 377-4 433-8
53 1.5 7.0 16.3 29.6 46'8 68'0 93.0
1220 154-9 191-8 2325 277.2 325-8 378-3 434.8
54 1.6 7.1 16.5 29.9 47.1 68.3 93.5 122.5 155-5 192-4 233-2 2780 3267 379-3 435-8
55 1.6 7.2 16.7 30.1 47'5 68.7 93.9 123.1 156-1 193-1 234-0 278.8 327.5 380-2 436-7
56 1.7 7.3 16.9 30.4 47'8 69.1 94.4 123.6 1567 193-7 2347 279-5 328 4 381-1 437-7
57 1.8 7.5 17.1 30.6 48'1 69.5 94.8
124.1 157.3 194-4 235 4 280-3 329 2 382-0 438-7
58 1.8 7.6 17.3 30.9 48.4 69.9 95.3
124.6 157.8 195 0 236 1 281-1 330-0 382-9 439.7
59 1.9 7.7 17.5 31.1 48.8 70.3 95'7 125 1 158-4 1957 236-8 281-9 330-9 383-8 440-6

Table XVIII. of Mr. Baily extends to 36 minutes from the meridian.