Setting a compass

[Mang]

I'm taking the Cubs through some map work tomorrow and I wanted to gen up on setting a compass, looked at several internet sites, and now I'm doubting myself as to whether you turn the compass ring clockwise or anti clockwise to allow for the magnetic variation!

Firstly, can someone confirm this and secondly, are there any good 'compassy' sites that can be recommended?

Cheers.

 

[John Fenna]

grid to mag - add -
mag to grid - get rid....

ie - when you take the compass off the map - add on the mag variation (turn ring anti clockwise,
When working from the compass and transfering the bearing to an OS map with a grid - subtract the mag variation (turn the ring clockwise)

 

[Walks with dogs]

Or, when going from big to small (ie ground to map) subtract. From small to big ( map to ground) add.

 

[g4ghb]

John is right on the nail however magnetic deviation may be a little advance with Cubs - In fact it takes a while for the Scouts to grasp the concept in my experience

Also if you head into semi-advanced compass work it limits the 'progressive training' element

Just my opinion though mate!

 

[Lardrover]

Second that, maybe work on the mapcraft and reading the map first before technical stuff like mag deviation. Probably not that easy atm this time of year as you've lost most, if not all, daylight on parade nights. Or see how they take it in and go from there. For me, it was always a drag having to work it out, same with timings. I knew I had to do it but in my own little world it hardly made a difference Now I can find myself on the flip side of the coin.

I did see a really good site with flash animation for compass work, looking for it now, will edit and paste the link if I do. I think it was a known site, not as high as DofE or Ordnance Survy, but not some unknown.

Found it: http://geographyfieldwork.com/UsingCompass.htm

In any case, Google is your friend if you are unsure.

 

[FGYT]

I would suggest learning the subject first for a bit before trying to pass it on tommorrow as an expert (which is what you will be to the Cubs )
getting it wrong now will just make it harder in the future for some one who knows what they are doing to sort it out.

sorry if thats a bit harsh but your post does read like you dont know much about map reading and navigation
i would just stick to identifying wwhat the pictures and lines on a map represent on the ground first maybe move on to orientating the map to ground using landmarks etc if the terain is suitable or if its dark and your in a hut make a landscape with a few land marks on the floor and draw out a hand map with symbols to match ( not to many )

ATB

Duncan

 

[MrEd]

^^^ agree with that, but if your going to use a compass perhaps explain how it works and what its for, and just briefly how its used with a map.

I did somthing similar with some of the St John Cadets ( 13/14ish so a bit older) on their summer camp once, we just looked at a map and explained the sympols, what the contour lines meant, and what the scales mean. the also learnt with the compass to take a bearing, as well as orientate the map to the ground.

they then went onto do more stuff with other instructors and it all culminated at the end of the week with a day hike,on a nice circular route in dorset. was great and they did really well, kept it simples. (admittedly the 3 instructors checked everything and could have walked the route without map - its was just footpaths but that wasnt the point lol

 

[forestwalker]

I always work it out from first principles (when I need to, since the Silva 15TD has a compensation setting). Remember that the magnetic north pole is just north of the Canadian mainland, and it becomes fairly clear.

But I agree that for Cubs teaching them the cardinal points, basic map features (roads, streams, etc) is probably about enough.

As a teacher I usually use a spiral staircase as a mental model. As you go up it you pass every point several times, but each time at a higher level. So the first time they meet the compass the cardinal points is sufficient, the next time 360 degrees (and taking out courses in degrees), the time after that you may take up declination.

 

[SimonM]

I wouldn't teach Cubs compass work for several reasons, not least:

• It can be difficult to grasp and so you may put them off.
• Even if they do learn the basics well, it leaves the poor Scout leader attempting to teach still more advanced material.

IMHO, stick with setting with the map by landmarks, conventional symbols and grid references.

OS have a very good resource page where you can download booklets and symbol flash cards etc...
http://www.ordnancesurvey.co.uk/oswebsite/education/teachingresources/index.html

HTH

Simon

 

[scrogger]

I agree with Simon. Just work on the Map it self the symbols etc. Maybe do a quiz or something. Also you could cut out some odd size curvy shapes in graduating sizes to help them to get their heads in gear to do with Contours I have just done this and it worked really well.

As regards Declination I was taught something similar to John.

GUMA grid unto Magnetic ADD
MUGS magnetis unto grid SUBTRACT

Have Fun!!! dont forget the Anadins!!!

 

[Carbuncle]

I wouldn't teach Cubs compass work for several reasons, not least:

• It can be difficult to grasp and so you may put them off.
• Even if they do learn the basics well, it leaves the poor Scout leader attempting to teach still more advanced material.

I'm a little bit inclined to disagree. If you take declination out of the equation, some aspects are super simple (1 and 2 of the silva 123 for e.g.). My lad had no trouble with it as a 7 year old (he's only 9 now). We're lucky in Western Europe in that for the forseeable any adjustment will be small, so it can be ignored. If you only do setting the map, that's 90% of compass usage covered, the kids can have confidence in the relative direction of features they're trying to locate. On the other hand, I've never tried to explain it to 50 hyped up cubs.

 

[scrogger]

In one respect carbuncle I agree my lad is 9 and can set the Map etc but it wasnt to easy to get it in there and it was one to one with me. As you say with a group of over excited cubs of as say 15 let alone 50!!!! lol I think I would be pulling my hair out.

 

[SimonM]

Remember that "even" at Bronze Duke of Edinburgh level, compass isn't an essential part of the nav ex - and that is aimed at 14year olds...so imagine teaching a group of 8 - 10 year olds.

Just not needed at that age for the vast majority of kids IMHO.

Simon

 

[Carbuncle]

Uh, and the easiest way to do the declination is to use the declination scale*, it's what it's for. It's printed on the inside of the capsule around the "shed", between the "W. Decl" and "E.Decl" text. If the variation is 5 deg west, point the needle at 5 deg west on the scale. Simples. The N-S lines in your capsules line up as before with the glid lines on the map and Bobs your mothers live-in boyfriend. No sums, no rhymes.

* Using Silva baseplate compasses or copies anyway. Better still use one with adjustable declination, e.g. Suunto M3. But anyway . . .

 

[bearbait]

Adding or subtracting variation when going from map to compass and v.v. depends on whether the magnetic pole is east or west of you.

You also need to know whether the magnetic variation shown, or given, on the map is from grid north or true north. And you also need to know whether the "north" on the map is true north or grid north. I agree that maps often state all these facts but there are occasions when you get magnetic variation from one source and the "north" (true or grid) from the map - a different source. Also some maps show, i.e. are gridded, magnetic north (which varies over time) and you may want to get back to true, or to a different grid north to correlate with a different map. It's also worth mentioning that not all maps are "north" up (he said remembering being caught out by this recently!).

The rule I use, going from true, or grid, bearing/course on map or chart to compass is "West Best (add variation), East Least (subtract variation)". A simple rule which can be readily modified to go the other way, and when other facts are taken into consideration. Variation is an important topic: whilst relatively small in the UK, in some parts of the world it is well in excess of twenty degrees - which makes a massive difference if you get it the wrong way round (or don't allow for it!).

Just to complicate magnetism and compasses a little further, if you're navigating at sea there's a further correction to apply: deviation. This is different for each vessel, can vary according to where the gear is stowed on the vessel - and varies according to the heading of the vessel. (Amazing we make landfall at all, really!)

As an earlier poster said, it is not a simple topic and a full understanding of the implications is necessary to teach to others. If you are teaching nav "global" principles should be taught, rather than what you do in the U.K.

 

[Carbuncle]

In one respect carbuncle I agree my lad is 9 and can set the Map etc but it wasnt to easy to get it in there and it was one to one with me. As you say with a group of over excited cubs of as say 15 let alone 50!!!! lol I think I would be pulling my hair out.

See what you mean, my wifes just gone to pick our kids up, I try to avoid it, they're hyper;-) They love it though, there's some fantasic people working with scouts these days, far better than when I was a kid.

 

[Basha72]

This may be of use follow the link

Looks pretty good to use with kids ...may even help some adults

http://mapzone.ordnancesurvey.co.uk/mapzone/PagesHomeworkHelp/docs/easypeasy.pdf

Basha

 

[Mang]

Blimey, 17 posts! Thankyou everybody. I only want to touch briefly on magnetic variation (just this)

when you take the compass off the map - add on the mag variation (turn ring anti clockwise)

The main night will be a (hopefully) fun quiz mainly finding clues using grid references. I've done Scouts and Cubs and nearly lost the will to live teaching basic mapping stuff to both sections.

 

[toonman]

lol
i've had a rough time boxing the compass to 14 year old scouts, can't imagine with cubs.

 

[jonajuna]

thanks for the thread, given lots of pointers to teaching my two, liking the os "easy peasey" leaflet