The Sun is actually only 700 miles away

According to this sacred text, in 1870 Rowbotham conducted an experiment to measure the distance of the sun. He arrived to a conclusion that the sun was ........ only 700 miles above his earth!!! But he didn't stop there. He also worked out that at the time of his experiment (July 13th), the sun was above Angoulême, France, 400 miles south of London. Was it really? Nonsense!!! Angoulême is at latitude 45° north and the sun never wanders above 23.5° N. People in Angoulême has never had the sun overhead. Ever!!! I am sure he never went to France to double check his claim. Or maybe he didn't know that Angoulême was only 400 miles south of London.

Oh well. One thing is certain, Rowbotham has made a ridiculously big mistake.

I extracted the method of his experiment and the associated pictures below.

The distance from London Bridge to the sea-coast at Brighton, in a straight line, is 50 statute miles. On a given day, at 12 o'clock, the altitude of the sun, from near the water at London Bridge, was found to be 61 degrees of an arc; and at the same moment of time the altitude from the sea-coast at Brighton was observed to be 64 degrees of an arc, as shown in fig. 58 (left figure below). The base-line from L to B, 50 measured statute miles; the angle at L, 61 degrees; and the angle at B, 64 degrees. In addition to the method by calculation, the distance of the under edge of the sun may be ascertained from these elements by the method called "construction." The diagram, fig. 58, is the above case "constructed;" that is, the base-line from L to B represents 50 statute miles; and the line L, S, is drawn at an angle of 61 degrees, and the line B, S, at an angle of 64 degrees. Both lines are produced until they bisect or cross each other at the point S. Then, with a pair of compasses, measure the length of the base-line B, L, and see how many times the same length may be found in the line L, S, or B, S. It will be found to be sixteen times, or sixteen times 50 miles, equal to 800 statute miles. Then measure in the same way the vertical line D, S, and it will be found to be 700 miles. Hence it is demonstrable that the distance of the sun over that part of the earth to which it is vertical is only 700 statute miles. By the same mode it may be ascertained that the distance from London of that part of the earth where the sun was vertical at the time (July 13th, 1870) the above observations were taken, was only 400 statute miles, as shown by dividing the base-line L, D, by the distance B, L. If any allowance is to be made for refraction--which, no doubt, exists where the sun's rays have to pass through a medium, the atmosphere, which gradually increases in density as it approaches the earth's surface--it will considerably diminish the above-named distance of the sun; so that it is perfectly safe to affirm that the under edge of the sun is considerably less than 700 statute miles above the earth.

         

It might be. It is difficult to achieve accuracy in these types of experiments.

It might be. It is difficult to achieve accuracy in these types of experiments.

"These types" of experiments where you assume the earth flat, yes... it's difficult to be correct when using incorrect assumptions and models. RE on the other hand, well you know Tom.

Quote from: Tom Bishop on September 04, 2013, 11:04:36 AM

It might be. It is difficult to achieve accuracy in these types of experiments.

"These types" of experiments where you assume the earth flat, yes... it's difficult to be correct when using incorrect assumptions and models. RE on the other hand, well you know Tom.

Not exactly. On the earth's distance from the sun Copernicus computed it as 3,391,200 miles, Kepler contradicted him with an estimate of 12,376,800 miles, while Newton had asserted that it did not matter whether it was 28 million or 54 million miles 'for either will do as well'.

I agree with newton that it wouldn't matter at that astronomical distance if we used methods like the trigonometric 45 degree one you used for your flat earth model. That method wasn't used to arrive at 93 million though.

It might be. It is difficult to achieve accuracy in these types of experiments.

FE sun cannot be at 700 miles and 3,000 miles at the same time. He made a mistake didn't he?

Quote from: Tom Bishop on September 04, 2013, 11:04:36 AM

It might be. It is difficult to achieve accuracy in these types of experiments.

FE sun cannot be at 700 miles and 3,000 miles at the same time. He made a mistake didn't he?

Nor can the sun be 3,391,200 and 12,376,800 miles at the same time under the Round Earth model. The discrepancy is clearly due to issues in accuracy.

Quote from: Cartesian on September 04, 2013, 12:00:03 PM

Quote from: Tom Bishop on September 04, 2013, 11:04:36 AM

It might be. It is difficult to achieve accuracy in these types of experiments.

FE sun cannot be at 700 miles and 3,000 miles at the same time. He made a mistake didn't he?

Nor can the sun be 3,391,200 and 12,376,800 miles at the same time under the Round Earth model. The discrepancy is clearly due to issues in accuracy.

How was the 3000 mile distance arrived at?

Quote from: Cartesian on September 04, 2013, 12:00:03 PM

Quote from: Tom Bishop on September 04, 2013, 11:04:36 AM

It might be. It is difficult to achieve accuracy in these types of experiments.

FE sun cannot be at 700 miles and 3,000 miles at the same time. He made a mistake didn't he?

Nor can the sun be 3,391,200 and 12,376,800 miles at the same time under the Round Earth model. The discrepancy is clearly due to issues in accuracy.

Nobody here has been quoted to say that the sun is 3,391,200 or 12,376,800 miles away. On the other hand YOU have been quoted at 3,000 miles and here is Cartesian showing you that your highly regarded Rowbotham calculated 700 miles. RE'ers do respect the process of science and we also recognize that these numbers can change when experiments are done incorrectly. Today things are different though. Today we can use radar signals to find the distance to Venus. Signals sent from earth will bounce off the surface of Venus and then travel back to earth where we can detect them. Because radar travels at the speed of light (a quantity that is well known from laboratory experiments) you can easily calculate the distance between Venus and Earth at any time.

distance = 0.5*(time for radar to travel both ways)*(speed of light)

 Now that we know the distance to Venus we can calculate the distance from the Earth to the Sun using trigonometry. Both Venus and Earth travel in almost perfect circles around the earth, so this is a fairly easy calculation. It might help to envision the situation if you draw two concentric circles on a piece of paper to represent the orbits of the Venus and Earth. Now imagine that the earth is set at one position in its orbit, as Venus travels along its orbit there are two points where the Venus-Sun line and the Earth-Sun are perpendicular (90 degrees apart). From our perspective on earth this is the point where Venus is the farthest it will get from the Sun. By keeping track of Venus over time we determine exactly when this will happen. When this happens we make the radar measurements mentioned above and we also measure the angle between the Sun and Venus at this point (here's where the trigonometry comes in!). It turns out that the distance from the Sun to the Earth is:

(distance of Sun-Earth) = (distance of Earth-Venus)*(cosine(angle))

This is how we get the distance of Sun-Earth to be 92,955,830 miles! This is also known as one astronomical unit (AU).

source: http://www.ucolick.org/~mountain/AAA/aaawiki/doku.php?id=what_is_the_easiest_way_to_measure_the_distance_between_the_earth_and_the_sun

Now that we know the distance to Venus we can calculate the distance from the Earth to the Sun using trigonometry. Both Venus and Earth travel in almost perfect circles around the earth, so this is a fairly easy calculation. It might help to envision the situation if you draw two concentric circles on a piece of paper to represent the orbits of the Venus and Earth. Now imagine that the earth is set at one position in its orbit, as Venus travels along its orbit there are two points where the Venus-Sun line and the Earth-Sun are perpendicular (90 degrees apart). From our perspective on earth this is the point where Venus is the farthest it will get from the Sun. By keeping track of Venus over time we determine exactly when this will happen. When this happens we make the radar measurements mentioned above and we also measure the angle between the Sun and Venus at this point (here's where the trigonometry comes in!). It turns out that the distance from the Sun to the Earth is:

(distance of Sun-Earth) = (distance of Earth-Venus)*(cosine(angle))

Made a to-scale diagram:
h can be calculated via the above method of signals from Earth.
α is the angular distance between the sun and Venus--easily measured directly from here.
a is, as rottingroom said above, equal to h * cos(α).

Quote from: Cartesian on September 04, 2013, 12:00:03 PM

Quote from: Tom Bishop on September 04, 2013, 11:04:36 AM

It might be. It is difficult to achieve accuracy in these types of experiments.

FE sun cannot be at 700 miles and 3,000 miles at the same time. He made a mistake didn't he?

Nor can the sun be 3,391,200 and 12,376,800 miles at the same time under the Round Earth model. The discrepancy is clearly due to issues in accuracy.

Different methods were used to calculate the 3,391,200 and 12,376,800 mile RE distances, so discrepancies are to be expected.  However, the same method was used to calculate the 700 and 3000 mile FE distances.  Why should the same method produce such wild discrepancies?  Also, who measured the 50 mile distance from London Bridge to the Brighton sea coast?

Quote from: Tom Bishop on September 04, 2013, 12:19:52 PM

Quote from: Cartesian on September 04, 2013, 12:00:03 PM

Quote from: Tom Bishop on September 04, 2013, 11:04:36 AM

It might be. It is difficult to achieve accuracy in these types of experiments.

FE sun cannot be at 700 miles and 3,000 miles at the same time. He made a mistake didn't he?

Nor can the sun be 3,391,200 and 12,376,800 miles at the same time under the Round Earth model. The discrepancy is clearly due to issues in accuracy.

How was the 3000 mile distance arrived at?

Later, Voliva used the same method as Rowbotham but did it at different locations (45 degree latitude) and at different time (at equinox around 20 March and 22 September). So on flat earth, the sun's altitude is not fixed. It depends on where and when you measure it.

Quote from: Cartesian on September 04, 2013, 12:00:03 PM

Quote from: Tom Bishop on September 04, 2013, 11:04:36 AM

It might be. It is difficult to achieve accuracy in these types of experiments.

FE sun cannot be at 700 miles and 3,000 miles at the same time. He made a mistake didn't he?

Nor can the sun be 3,391,200 and 12,376,800 miles at the same time under the Round Earth model. The discrepancy is clearly due to issues in accuracy.

Your statement can be misleading Tom. Science and technology progresses every day, and the measurement becomes more precise as we progress. Copernicus lives in 16th century. Kepler with his laws of planetary motion didn't really measure the sun's distance. He was more interested in calculating the ratio between the distance of each planet to the sun. For example, Mars-Sun is 1.52 x Earth-Sun regardless how far Earth-Sun was.

Today rounders accept that the sun is 93 million miles away. Not 3 million nor 12 million.

And what about the sun's distance in FE model? The altitude is not fixed. It is not an issue with accuracy. FE sun will never have a fixed altitude regardless how accurate you measure its elevation angle. Nowadays, not only you can measure this angle with a very high precision but you can also predict the elevation angle in a given location on earth and time, obviously using RE calculation method.

Try to repeat Rowbotham or Voliva experiment (both guys use the same triangulation technique) in different location and time, you'll come up with different figure every time (just like Rowbotham and Voliva did).

Quote from: Rama Set on September 04, 2013, 12:22:55 PM

Quote from: Tom Bishop on September 04, 2013, 12:19:52 PM

Quote from: Cartesian on September 04, 2013, 12:00:03 PM

Quote from: Tom Bishop on September 04, 2013, 11:04:36 AM

It might be. It is difficult to achieve accuracy in these types of experiments.

FE sun cannot be at 700 miles and 3,000 miles at the same time. He made a mistake didn't he?

Nor can the sun be 3,391,200 and 12,376,800 miles at the same time under the Round Earth model. The discrepancy is clearly due to issues in accuracy.

How was the 3000 mile distance arrived at?

Later, Voliva used the same method as Rowbotham but did it at different locations (45 degree latitude) and at different time (at equinox around 20 March and 22 September). So on flat earth, the sun's altitude is not fixed. It depends on where and when you measure it.

Tom and I know this, but Tom also claimed that the measurements have likely never been verified and so on his own view¹ the 3000 mile distance should be disqualified. Yet, he still believes it.

1-Specifically that assumptions, rather than confirmed measurements, destroy the credibility of factual knowledge.

Tom has been contradicting himself lately regarding latitude vs distance. He kept debating that 1° latitude was not equal to approx. 69 miles and insisted on everyone to measure it themselves. Then he was presented with the Voliva drawing that showed that 45° latitude was 3,000 miles to the equator, he couldn't prove that Voliva measured that distance himself. He went quiet since then.

I don't see how I am contradicting myself. 3000 miles divided by 45 is not 69 miles.

3000 miles is not my claim regardless, and is something Thomas Winship/Voliva came up with. Any quotes you find of me explaining how the distance to the sun was found is merely me explaining parts of the Flat Earth model.

When you explain that the sun is 93 million miles away, should we assume that you personally came up with the figure, performed the experiments and vetted the results?

I don't see how I am contradicting myself. 3000 miles divided by 45 is not 69 miles.

3000 miles is not my claim regardless, and is something Thomas Winship/Voliva came up with. Any quotes you find of me explaining how the distance to the sun was found is merely me explaining parts of the Flat Earth model.

When you explain that the sun is 93 million miles away, should we assume that you personally came up with the figure, performed the experiments and vetted the results?

When you say:

The sun is both 3000 miles away, and 93 million miles away, depending on the shape of the earth assumed.

And we know that you assume the Earth is flat, how could we assume other than that this is what you believe is a fact?  If we are misinterpreting you, it is your fault, because you leave no room to think otherwise.

Here are other instances of you stating you believe that celestial bodies have an altitude of 3000 miles:

http://www.theflatearthsociety.org/forum/index.php/topic,58482.msg1491228.html#msg1491228
http://www.theflatearthsociety.org/forum/index.php/topic,59731.msg1532895.html#msg1532895
http://www.theflatearthsociety.org/forum/index.php/topic,52543.msg1291279.html#msg1291279
http://www.theflatearthsociety.org/forum/index.php/topic,56662.msg1418629.html#msg1418629
http://www.theflatearthsociety.org/forum/index.php/topic,55198.msg1370817.html#msg1370817

Combined with other threads where you make no effort to disabuse anyone of the notion that you do not believe the sun to be at an altitude of 3000 miles, we are left with little choice except to think that you are being disingenuous now and actually do believe the sun's altitude to be 3000 miles on bad evidence and faulty methodology.  Unless you have a recantation of the orthodox FE position you would like to give?

3000 miles divided by 45 is not 69 miles.

My point was why you believed the figure given by Voliva without knowing how he obtained that figure. 3,000 divided by 45 is close to 69. And anyway, Voliva got the figure wrong, normally it should be 3,127 miles. Don't tell me that Voliva figure is correct because you don't know how he got it.

3000 miles is not my claim regardless, and is something Thomas Winship/Voliva came up with. Any quotes you find of me explaining how the distance to the sun was found is merely me explaining parts of the Flat Earth model.

Yeah I found plenty of your posts about this using the search facility. Rama found some too. So why did you use that figure if you don't believe it yourself? Don't you have to measure it yourself before you can say it out loud. You also said below that ENaG demonstrated that the earth was flat. You believe that the earth is flat just because your 100-year old book says so?

The only thing known about the celestial bodies is their distance from the earth. The 3000 and 3100 mile figures for the celestial bodies are based on triangulation in conjunction with a plane surface. Since the earth is flat, as demonstrated in Earth Not a Globe, simple trig can show that the celestial bodies are very close to the earth, and thus very small bodies.

When you explain that the sun is 93 million miles away, should we assume that you personally came up with the figure, performed the experiments and vetted the results?

No, I didn't. I don't have to measure it myself because I believe in how science operates. The method used to measure this is publicly available so anyone, I mean anyone, can verify its validity and reproduce it too.

I use that figure because it is part of the current Flat Earth model, the topic of discussion in each of the threads linked. I don't need to state "according to so and so" because the context of discussion is obvious. No one is expecting you to list "according to so and so" when you state that the sun is 93 million miles away. If anyone wants to know who and how, they will either ask or look it up. I expect the same courtesy.

Of course, the accuracy of the underlying figures lays with the people who made those theories. I even posted in this thread that the sun may very well be 700 miles, as Rowbotham states, due to difficulties in accuracy in this sort of experiment.

I expect the courtesy of a poster representing their beliefs honestly, so if you scratch my back, I will scratch yours.  I am not sure what is so difficult about this experiment.  Do you think there are no reliable surveying techniques?  Do you think we cannot measure the angle of the sun in the sky?  Or is it the trigonometry you think is difficult? 

I use that figure because it is part of the current Flat Earth model, the topic of discussion in each of the threads linked. I don't need to state "according to so and so" because the context of discussion is obvious. No one is expecting you to list "according to so and so" when you state that the sun is 93 million miles away. If anyone wants to know who and how, they will either ask or look it up. I expect the same courtesy.

You are not zetetic are you Tom?

Of course, the accuracy of the underlying figures lays with the people who made those theories. I even posted in this thread that the sun may very well be 700 miles, as Rowbotham states, due to difficulties in accuracy in this sort of experiment.

We are in 21st century now Tom. For example you can find many sun telescopes which you can mount it on a computerized tripod that can give you accurate heading and elevation. Or if you don't want to spend too much money, then participate to the cheap experiment proposed by Alex in http://www.theflatearthsociety.org/forum/index.php/topic,59779.msg1535356.html#msg1535356

It's not about accuracy, it's about your willingness.

I use that figure because it is part of the current Flat Earth model, the topic of discussion in each of the threads linked.

Yet you refuse to understand why that part of the flat earth model is fundamentally flawed.

Of course, the accuracy of the underlying figures lays with the people who made those theories. I even posted in this thread that the sun may very well be 700 miles, as Rowbotham states, due to difficulties in accuracy in this sort of experiment.

I would contend that an error of more than 400% in Rowbotham's calculation compared to Voliva's calculation using essentially the same method suggests that there are more errors in the experiment than just the accuracy of Rowbotham's measurements.

I expect the courtesy of a poster representing their beliefs honestly, so if you scratch my back, I will scratch yours.  I am not sure what is so difficult about this experiment.  Do you think there are no reliable surveying techniques?  Do you think we cannot measure the angle of the sun in the sky?  Or is it the trigonometry you think is difficult?

Angles are not easy to measure on objects at great distances, especially not one as bright as the sun with no defined center-point, or one which must be preformed at a precise moment in time with another far off observer doing it simultaneously, and when the distances on the map you are using may be tainted and RE-based. There are plenty of ways errors can pop up in triangulation.

Quote from: Tom Bishop on September 05, 2013, 11:17:14 AM

I use that figure because it is part of the current Flat Earth model, the topic of discussion in each of the threads linked. I don't need to state "according to so and so" because the context of discussion is obvious. No one is expecting you to list "according to so and so" when you state that the sun is 93 million miles away. If anyone wants to know who and how, they will either ask or look it up. I expect the same courtesy.

You are not zetetic are you Tom?

The philosophy of Zeteticism is not "you have to see it to believe it." Read this discussion for a few pages.

Quote from: Rama Set on September 05, 2013, 11:29:26 AM

I expect the courtesy of a poster representing their beliefs honestly, so if you scratch my back, I will scratch yours.  I am not sure what is so difficult about this experiment.  Do you think there are no reliable surveying techniques?  Do you think we cannot measure the angle of the sun in the sky?  Or is it the trigonometry you think is difficult?

Angles are not easy to measure on objects at great distances, especially not one as bright as the sun with no defined center-point, or one which must be preformed at a precise moment in time with another far off observer doing it simultaneously. There are plenty of ways errors can pop up.

Many people are watching the sun as a hobby. This is just baseless. You gave up before you even try.

Quote from: Cartesian on September 05, 2013, 11:35:31 AM

Quote from: Tom Bishop on September 05, 2013, 11:17:14 AM

I use that figure because it is part of the current Flat Earth model, the topic of discussion in each of the threads linked. I don't need to state "according to so and so" because the context of discussion is obvious. No one is expecting you to list "according to so and so" when you state that the sun is 93 million miles away. If anyone wants to know who and how, they will either ask or look it up. I expect the same courtesy.

You are not zetetic are you Tom?

The philosophy of Zeteticism is not "you have to see it to believe it." Read this discussion for a few pages.

The term Zetetic is derived from the Greek verb Zeteo; which means to search, or examine; to proceed only by inquiry; to take nothing for granted, but to trace phenomena to their immediate and demonstrable causes.

Did you proceed by inquiry Tom? Did you trace the phenomena to their immediate and demonstrable causes?

Many people are watching the sun as a hobby. This is just baseless. You gave up before you even try.

How many people are measuring the angle of the sun, a blinding hot ball with no defined center-point, at a precise angle, at the exact moment in time someone else is doing it on a distant point on earth? It's not an "easy" experiment, especially considering that the long-distance accuracy of maps used to gauge distance between the observers may be inaccurate and RE-based.

The term Zetetic is derived from the Greek verb Zeteo; which means to search, or examine; to proceed only by inquiry; to take nothing for granted, but to trace phenomena to their immediate and demonstrable causes.

Did you proceed by inquiry Tom? Did you trace the phenomena to their immediate and demonstrable causes?

The definition of Zeteo - "to search, or examine; to proceed only by inquiry; to take nothing for granted, but to trace phenomena to their immediate and demonstrable causes" does not necessitate that you have to do it yourself. It can also mean that you need to collect a body of evidence in your inquiry. "Trust only yourself" is not implied in that definition.

I would suggest reading Earth Not a Globe for a direct meaning.

Quote from: Cartesian on September 05, 2013, 12:06:40 PM

Many people are watching the sun as a hobby. This is just baseless. You gave up before you even try.

How many people are measuring the angle of the sun, a blinding hot ball with no defined center-point, at a precise angle, at the exact moment in time someone else is doing it on a distant point on earth? It's not an "easy" experiment, especially considering that the maps themselves may be inaccurate and RE-based.

Every navigator prior to 1950 (and quite a few after). Also, hobbyists.

Relatedly, I and Scintific Method and anyone else who cares to are a few weeks away from just such an experiment. And that experiment will give us the answer in terms of the distance from the north pole to the equator which can be measured at a later date.

Quote from: Tom Bishop on September 05, 2013, 12:22:20 PM

Quote from: Cartesian on September 05, 2013, 12:06:40 PM

Many people are watching the sun as a hobby. This is just baseless. You gave up before you even try.

How many people are measuring the angle of the sun, a blinding hot ball with no defined center-point, at a precise angle, at the exact moment in time someone else is doing it on a distant point on earth? It's not an "easy" experiment, especially considering that the maps themselves may be inaccurate and RE-based.

Every navigator prior to 1950 (and quite a few after). Also, hobbyists.

Relatedly, I and Scintific Method and anyone else who cares to are a few weeks away from just such an experiment. And that experiment will give us the answer in terms of the distance from the north pole to the equator which can be measured at a later date.

Every navigator prior to 1950 has performed accurate triangulation experiments on the sun with another distant partner simultaneously? Please post this data.

Quote from: Cartesian on September 05, 2013, 12:06:40 PM

Many people are watching the sun as a hobby. This is just baseless. You gave up before you even try.

How many people are measuring the angle of the sun, a blinding hot ball with no defined center-point, at a precise angle, at the exact moment in time someone else is doing it on a distant point on earth? It's not an "easy" experiment, especially considering that the long-distance accuracy of maps used to gauge distance between the observers may be inaccurate and RE-based.

People look into the sun either for fun or professional reason using sun or solar telescope. Google or youtube it. But again as I said, if you just want to measure the elevation angle, there are ways to do it. Including a cheap experiment that doesn't involve looking directly to the sun proposed by Alex in another thread.

Quote

The term Zetetic is derived from the Greek verb Zeteo; which means to search, or examine; to proceed only by inquiry; to take nothing for granted, but to trace phenomena to their immediate and demonstrable causes.

Did you proceed by inquiry Tom? Did you trace the phenomena to their immediate and demonstrable causes?

The definition "to search, or examine; to proceed only by inquiry; to take nothing for granted, but to trace phenomena to their immediate and demonstrable causes" does not necessitate that you have to do it yourself. It can also mean that you need to collect a body of evidence in your inquiry. "Distrust others" is not implied in that definition.

I would suggest reading Earth Not a Globe for a direct meaning.

What body of evidence have you got in relation to the altitude of the sun? The 100-year old book or drawing?

Quote from: Alex Tomasovich on September 05, 2013, 12:35:33 PM

Quote from: Tom Bishop on September 05, 2013, 12:22:20 PM

Quote from: Cartesian on September 05, 2013, 12:06:40 PM

Many people are watching the sun as a hobby. This is just baseless. You gave up before you even try.

How many people are measuring the angle of the sun, a blinding hot ball with no defined center-point, at a precise angle, at the exact moment in time someone else is doing it on a distant point on earth? It's not an "easy" experiment, especially considering that the maps themselves may be inaccurate and RE-based.

Every navigator prior to 1950 (and quite a few after). Also, hobbyists.

Relatedly, I and Scintific Method and anyone else who cares to are a few weeks away from just such an experiment. And that experiment will give us the answer in terms of the distance from the north pole to the equator which can be measured at a later date.

Every navigator prior to 1950 has performed accurate triangulation experiments on the sun with another distant partner simultaneously? Please post this data.

Who said about triangulation experiment? Sailors used and still use sextant to measure the elevation of the sun at solar noon.

A sextant is an instrument used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon which is known as the object's altitude. Making this measurement is known as sighting the object, shooting the object, or taking a sight and it is an essential part of celestial navigation. The angle, and the time when it was measured, can be used to calculate a position line on a nautical or aeronautical chart. Common uses of the sextant include sighting the sun at solar noon and sighting Polaris at night, to find one's latitude

http://en.wikipedia.org/wiki/Sextant