INDEX
- A
- Acceleration for longitude, 91
- Amplitude, 12, 97
- Aphelion, 8
- Apogee, 139
- Astronomical triangle, 102
- Azimuth, 12, 96
- altitude, 98
- Weir’s diagram of, 98
- Azimuths and amplitudes, 93
- C
- Calendar, 64
- Celestial latitude, 14
- longitude, 14
- Chart, contours, 155
- corrections, 151
- scales, 152
- Charts, 146
- datum, 155
- diagrams of symbols, 156
- fathom curves, 158
- information on, 154
- symbols, 152
- Chronometer time, necessity of accuracy in, 87
- Circles of equal altitudes, 110
- Circum-meridian altitude, 82
- Compass, 93
- deviation of, 94
- error of, 94
- naming of, 99
- Coordinates, 9
- Corrections for observed altitudes, 68
- D
- Day lost and day gained, 37
- Dead reckoning, 1
- Declination, 15
- daily change of, 24
- Deviation, naming of, 100
- Dip, 72
- Double altitude problem, 120
- E
- Earth’s orbit, 8
- revolution around the sun, 20
- Eclipses, 141
- Ecliptic, 14
- Equal altitude circle, 109
- Equal altitude method, 104
- Equation of Time, 56
- diagram of, 62
- error due to obliquity, 60
- Equinoctial colure, 26
- Ex-meridian altitude, 82
- bodies below the pole, 86
- planets, 86
- stars, 86
- F
- First point of Aries, 14, 26
- G
- Gnomonic chart, 150
- Great circles, 10, 17
- Great-circle sailing, 150
- Greenwich mean time on navigator’s watch, 54
- H
- Horizon, rational, 11, 75
- sensible, 12, 73
- visible, 11, 73
- Hour circles, 13
- I
- Index correction, 68
- J
- Johnson’s method, 123
- diagrams, 126
- K
- Kepler’s Law, 56
- L
- Latitude, 78
- by Polaris, 88
- factor, 129
- formula for finding, 80
- Laying a course, 96
- Lights, characteristics, etc., 153
- Longitude, 101
- and time, 102
- by equal altitudes, 104
- factor, 125
- prime vertical, 103
- stars and planets, 105
- Lunar cycle, 143
- M
- Mean time into sidereal, 106
- Mercator Projection, 146
- diagram, 147
- Meridian altitude, 78
- time to observe a star, 81
- to report at noon, 81
- Meridional parts, 149
- Middle latitude sailing, 4
- Mizar, 89
- Moon, 139
- full, 140
- harvest, 143
- new, 140
- Moon’s declination, 143
- diagram, 144
- nodes, 143
- retardation, 142
- revolution, 140
- right ascension, 142
- N
- Nadir, 11
- Napier’s diagram, 96
- Nautical astronomy, 5
- New navigation, 102, 129
- advantages of, 133
- diagrams of, 135, 137
- finding position without plotting on chart, 138
- illustrated examples, 134
- Notices to mariners, 151
- Nutation, 32
- P
- Parallax, 75
- horizontal, 76
- moon, 77
- Parallel sailing, 3
- Perigee, 139
- Perihelion, 8
- Plane sailing, 2
- Planets, 6-7
- Polaris, 88
- diagram, 90
- time to take sight, 92
- Precession of the equinoxes, 27
- causes of, 31
- Prime vertical, 12
- observations on, 103
- Q
- Quadrature, 140
- R
- Refraction, 71
- Rhumb line, 149
- Right ascension, 26, 50
- S
- Sailings, 3
- Seasons, the, 20
- Semi-diameter, 69
- Ship’s time, 40
- Sidereal time, 43
- (local) how to obtain, 52
- longitude from, 53
- year, 66
- Solar system, 5
- Summer, length of northern and southern, 25
- lines, as chords and tangents, 112
- when under the sun, 121
- Sumner, Capt., his experience, 107
- line, displacement of, 118
- tangent method, 114
- value of, 115
- method, 107
- Sun’s change in azimuth, 120
- eastward movement, 16
- T
- Time diagram, 51
- Tropical year, 66
- V
- Vega as a pole star, 31
- Vernal equinox, 20
- dates of, 67
- Vertical circles, 12
- W
- Weir’s azimuth diagram, 98
- Z
- Zenith, 10