Why use Celestial Navigation?

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bambodoggy

Bushcrafter (boy, I've got a lot to say!)
Nov 10, 2004
3,062
50
49
Surrey
www.stumpandgrind.co.uk
Tony said:
I know that we’ve had a couple of threads on here about celestial navigation, but is it something we should still worry about learning and passing on to our children? In this day and age of gadgets the world has become a much smaller place, how often do we need to look up into the sky and say….”ahh, that’s there, that’s over there, so this is the way to go” Ahs it a practical use or do we learn it because it’s an old skill?

When I joined the TA and was re-taught basic map reading the subject of using the stars came up and our staff nco took us outside...it turned out I knew more than he did about it (which he took very well unlike some I know and allowed me to impart my knowledge on the group) but just the fact that it came up impressed me... we went on to learn micro-navigation to pin point accuracy for various military tasks that required it but I was still impressed that they bothered to go right back to basics to teach everybody the same thing...ok I had to sit through lectures that I already understood from cubs, scouts, Cadets and my MLTB Summer leaders but hey...it never hurts to get a refresher! :eek:):
 

Stevie

Tenderfoot
Feb 21, 2005
67
0
Kidderminster
spamel said:
Although I think GPS are amazing inventions, and owning an old Garmin 12 aswell, I still like to use my core navigation skills, and only use GPS as a verifying tool. If you rely on GPS and it goes wrong, either due to battery failure or breakage, and you don't have a good grasp of map and compass navigation, you are screwed.

Finding north with an analogue watch is very interesting, and ensuring the watch is accurate so will your direction. Stars are good, although you have to be on top of the knowledge, there can't be any grey areas. They were used for centuries by our forefathers, and it worked for them. I would like to get a greater knowledge of celestial navigation, if anybody can send me to a good book or website, it would be greatly appreciated.

I agree, I've always used a compass and maps where available. On occasions I have also made my own map. I bought a GPS unit the other week. It's a great piece of kit but like you say, a flat battery or some damage and you're stranded. I'll still use my compass first GPS second! :newbie:
 

Kirruth

Forager
Apr 15, 2005
109
0
56
Reading
www.bayes.org.uk
The trick with the hour hand of a watch is that with the hour hand pointed at the sun, south is halfway between the hour hand and twelve o'clock on the watch face. The watch needs to be on GMT. Might not work well if it's a digital watch :)
 

brynbach

Full Member
Mar 1, 2005
11
0
61
North Wales
spamel said:
I would like to get a greater knowledge of celestial navigation, if anybody can send me to a good book or website, it would be greatly appreciated.

I've recently got a great book by Harold Gatty - Finding Your Way WIthout Map or Compass. It covers all aspects using eyes. ears, smell, reflections, wind, trees and plants, animals, sun, moon and stars etc etc.

Got mine from www.abe.com

Hope this helps

cheers
Carl
 

Great Pebble

Settler
Jan 10, 2004
775
2
54
Belfast, Northern Ireland
Celestial navigation is a great skill to have. I won't say essential because I don't/i] reckon it is. But (one of these in a lot of my posts) it's likely to let you down when you might need it most, in really crap weather. Compasses, loads of them.
 

pumbaa

Settler
Jan 28, 2005
687
2
50
dorset
I feel that a big part of "camping" however you do it , is being under the stars . You can literaly lose hours looking into them . Also i look at navigation by the stars in almost the same way as we were taught maths at skool , We were allowed to use a calculator (or in this case compass) but you had to give an aproximate margine so you new it wasnt leading you up the garden path !! If you know where north is , either by stars or moss etc. then you should know roughly which direction you should be traveling in . If your compass or gps points in roughly the same direction as your estimation then you know your headed the right way !
Pumbaa
 

ChrisKavanaugh

Need to contact Admin...
"Second star on the right, then straight on till morning" works a lot better than "Wendy, when your done stitching my shadow nick me some double A batteries for my GPS." I remember when the Coast Guard dropped formal instruction with the sextant. I watched this new ensign run his career aground laughing at the vintage brass sextant in it's velvet lined mahogany box. It was the skipper's prize possession and he personally double checked our GPS position AND the WW2 vintage issue sextants we few still took reassuring shoots with among the video game laughingly called a bridge. Personally, I go home to purge myself of all this deux ex machina gadgetry. The stars are part of that wonder and bending myself to their ancient paterns is no different than snuggling deep into a leaf shelter.
 

Kirruth

Forager
Apr 15, 2005
109
0
56
Reading
www.bayes.org.uk
spamel said:
Kirruth, it all depends what hemisphere you are in!!

It does: the same trick points north in the Southern Hemisphere (which is where I learned it), but you point 12 at the sun and go half the angle to the hour hand.

The stars are funny down there too :)
 

Eric_Methven

Bushcrafter (boy, I've got a lot to say!)
Apr 20, 2005
3,600
42
73
Durham City, County Durham
I like using a cross staff to find latitude. It was invented in the twelvth century and was a precursor to an astrolabe which was a precursor to the sextant. You can make a cross staff from five sticks in about an hour, and with mine, I can find any latitude from equator to the poles. Great fun to make, and a great feeling of satisfaction when double checked with a GPS and you find you are spot on. They are also a great way of teaching kids about celestial navigation.

Eric
 

pumbaa

Settler
Jan 28, 2005
687
2
50
dorset
Have you got any pictures or information on how to make/use them ?
I quite fancy having a go at that .
Cheers
Pumbaa
 

Goose

Need to contact Admin...
Aug 5, 2004
1,797
21
56
Widnes
www.mpowerservices.co.uk
pumbaa said:
Have you got any pictures or information on how to make/use them ?
I quite fancy having a go at that .
Cheers
Pumbaa
This site any good for a start? My head is fizzing trying to remember the basic maths!
But it does look quite good, just need to be in the mood to study it.
 

Moonraker

Need to contact Admin...
Aug 20, 2004
1,190
18
61
Dorset & France
pumbaa said:
Have you got any pictures or information on how to make/use them ?
I quite fancy having a go at that .
Cheers
Pumbaa
Here you go Chris:

"From Stargazers to Starships" by David P. Stern - The Cross Staff


Crstaf5.gif


Another nice site with instructions how to make a simple wooden one:


Making a Simple Cross-Staff

ESI.x-pcs.jpg


Or alternatively try making a Kamal "The Kamal was used by Arab sailors since ancient times."

The Kamal - Richard A. Paselk


ESI.Kamal.jpg


Looks more bushcrafty to me :) Perhaps not quite so useful though?

Simon
 

Eric_Methven

Bushcrafter (boy, I've got a lot to say!)
Apr 20, 2005
3,600
42
73
Durham City, County Durham
A cross staff is easy enough to make. I take a piece of wood 3/4" square or so, and about 36" long. Then I make four cross pieces from strips of thin wood 1/4" thick by 2" wide. The lengths are important. The smallest is 21/2" long, the next is 5" followed by 10" and lastly a piece 20" long. I make a square hole in the centre big enough for the long stick to fit through so it slides up and down without sticking. On the back of each crosspiece I glue a small block again with a square hole so the crosspiece doesn't wobble when on the stick.

With my method you don't need the math to work out your latitude, I do it so the degrees are marked on the stick already. There are four sides to the stick, one for each of the crosspieces. The smallest one goes from two dgrees up to forty degrees, the five inch one goes from twenty degrees up to sixty, the ten inch crosspiece goes from thirty to eighty degrees and the twenty inch goes from forty to ninety degrees.

To use it, you fit the crosspiece to the stick, and hold the end of the stick up to your eye. You slide the crosspiece down the stick until the bottom edge of the crosspiece lines up with the horizon and the top edge of the crosspiece lines up with polaris. Then you take the reading off the stick where the crosspiece intersects it.

When you reach a latitude where you can't get a reading, you change to either a smaller crosspiece (if sailing south) or larger crosspiece (if sailing north).

So, to sumarise, you have a square stick with scales marked on all four sides. You have a crosspiece for each scale, four in all that you use depending on your latitude. The crosspieces are stiffened on the back with a block of wood to give stability on the stick.

To mark the scale you need to do the following:

Take a sheet of wallpaper lining paper and draw a line down one edge. Make it as long as the stick.

At one end of the line, mark it off as the eye end and the other mark off as polaris end.

At the eye end, take a protractor and draw lines outward every 5 degrees, so there are a series of equally spaced lines radiating out from the end of the line at the eye end of the paper. These lines will represent spacings of ten degrees on the stick. The reason for five degree spacings representing ten degrees on the stick is that we are only measuring half of the crosspiece, so we have to double up. (You'll see what I mean when you try it).

Once the degrees are drawn, mark a line parallel to the first line you drew, exactly half the length of the crosspiece, so the first will be 11/4" in from the main line. The next will be 21/2" in followed by a line 5" in and finally a line drawn 10" in.

Place the stick on the 11/4" line and mark where the line intersects with the degree lines. With five degrees being the radiating line nearest the original line, and ninety degree line being at forty five real degrees to the original line (if that sounds confusing remember that five real degrees is representing ten degrees on the stick, because we are only measuring one half of it.)

Once the intersection lines are marked, and the degrees noted, turn the stick over a quarter turn and do the same on the next line out, the 21/2" line representing the five inch crosspiece. Mark once again where the radiating lines intersect the parallel line and so on until all four side of the stick are marked off in varying degrees.

The best way to keep these marks from wearing away is to cut nicks across the stick with a knife and either stamp the degrees into the wood or use a dremel with an engraving bit to permanently mark the wood with the degrees.

Once made, give all pieces a good wax with beeswax to protect the wood and help with smooth sliding of the crosspiece.

So, to use the thing, you hold the stick up to your eye and slide the crospiece up or down until the bottom is on the horizon and the top is on polaris and read off the degrees on the stick. If you are on the equator, polaris will look like it is on the horizon so you'd have the smallest crosspiece way out on the end of the stick. If on the other hand you are up north and polaris is right above you, you'll need the longest crosspiece and it will be nearer your face when you take the measurement.

I really hope that is clear, I'm just typing it all from memory. Just ask if you need clarification on any aspect of it.

Oh yes, nearly forgot. This instrument is for astral navigation only. Never try to take a sun sighting with it or you'll end up with retinal burns. There's a different kind of cross staff for sun sighting that you use with your back to the sun and rely on the shaddow cast to give the reading, but that's for another day.

Eric
 

pumbaa

Settler
Jan 28, 2005
687
2
50
dorset
Thanks I am going to have to give that a go .
Do you think that the size of the crossed sticks makes any difference ? I was thinking of a pocket sized one !
Pumbaa
 

Eric_Methven

Bushcrafter (boy, I've got a lot to say!)
Apr 20, 2005
3,600
42
73
Durham City, County Durham
Pumbaa, you can make a pocket one but remember to keep the scale relative. Use the method I describe for marking the degrees and use half the crosspiece size when marking off. Also, the smaller it is, the less accurate it will be. The original users needed two people to take a reading as the staff was nearly twelve feet long and they only used one crosspiece.

Eric
 

Wayland

Hárbarðr
arctic hobo said:
the Vikings used a "lodestone" (magnetic rock) compass for navigation.

The use of lodestone by the Vikings is uncertain but possible. Most of their deep sea navigation appears to have been achieved using a bearing dial or "sun compass"

I have tried one of these devices myself and they have the advantage of needing no modern equipment to make or set up, all can be done by observation.
 

AJB

Native
Oct 2, 2004
1,821
9
56
Lancashire
Living about 40 miles from Manchester and about 10 from Preston, I don’t remember the last time I saw a star (I sometimes see that guy who used to run the supermarket in Coronation Street in the town centre, but that’s about it)

Bloody Light Pollution
 

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