Bob Blaylock
Diamond Member
- Banned
- #1
Some time, a few decades ago, I remember by father seeing a sextant advertised, and buying it. His interest in such an instrument, of course, makes sense, given that some decades before that, around the time I was born, he was a navigator in the Air Force. That was long before such things as GPS; when navigation necessarily involved the use of an instrument such as a sextant, to take sightings on the sun and the moon and the stars, and to determine one's location by that means.
On receiving and inspecting his sextant, I recall that he declared that it really wasn't a very good usable sextant, that it appeared to have been built more for show/display than for any actual use as navigational instrument.
Much more recently, after my mother passed away, this sextant came into my possession.
I never really thought about old-school navigation, until some time within the last few months, when it occurred to me that one basic principle seemed obvious. If I had a sextant, and knew how to use it, then on any night when I had a clear view of the night sky, and of the horizon, anywhere very far into the northern hemisphere, I should be able to easily determine my latitude.
As it happens, the north end of the Earth's rotational axis points almost exactly to a star called Polaris, the North Star. Anywhere on Earth from where this star is visible, it's angle above the horizon should almost exactly equal the latitude of the place from which is is being observed. I thought of my father's sextant, now buried in a closet and decided to get it out and see if I could figure out how to use it.
After playing with it for a while, I was able to get a rough sense of how it is supposed to work, but alas, what I remember of my father's observation about its quality is rather greatly overstated. I think I was able to figure out how to use it, but it's quality is so poor that I do not think it is possible to get a usable sighting on a star with it. Possibly on something as big and bright as the Sun or the Moon, but not on a star.
Well, if I can't use it as an actual astronomical/navigational instrument, at least I can use it as something to photograph.
So here is my photograph of my father's sextant…
And here it is, in red/blue anaglyph 3D. Put on a pair of standard red/blue 3D glasses to properly view this second image.
On receiving and inspecting his sextant, I recall that he declared that it really wasn't a very good usable sextant, that it appeared to have been built more for show/display than for any actual use as navigational instrument.
Much more recently, after my mother passed away, this sextant came into my possession.
I never really thought about old-school navigation, until some time within the last few months, when it occurred to me that one basic principle seemed obvious. If I had a sextant, and knew how to use it, then on any night when I had a clear view of the night sky, and of the horizon, anywhere very far into the northern hemisphere, I should be able to easily determine my latitude.
As it happens, the north end of the Earth's rotational axis points almost exactly to a star called Polaris, the North Star. Anywhere on Earth from where this star is visible, it's angle above the horizon should almost exactly equal the latitude of the place from which is is being observed. I thought of my father's sextant, now buried in a closet and decided to get it out and see if I could figure out how to use it.
After playing with it for a while, I was able to get a rough sense of how it is supposed to work, but alas, what I remember of my father's observation about its quality is rather greatly overstated. I think I was able to figure out how to use it, but it's quality is so poor that I do not think it is possible to get a usable sighting on a star with it. Possibly on something as big and bright as the Sun or the Moon, but not on a star.
Well, if I can't use it as an actual astronomical/navigational instrument, at least I can use it as something to photograph.
So here is my photograph of my father's sextant…
And here it is, in red/blue anaglyph 3D. Put on a pair of standard red/blue 3D glasses to properly view this second image.
