The Great Newlands Trigonometrical Survey
Contents
Information
Created By: Jonny Huck
Currently Used By: Jonny Huck
Location: Newlands Valley (requires transport to Little Town)
Instructions
Get te group on a minibus and transport them to the car park at Little Town.
Give out the equipment (put each person in charge of something that they then have to bring back!) and set off along the path towards Newlands Valley.
About half way there, stop where you can see the white building and there is space amongst the bracken to set up a tripod. Give them a bit of chat about Triangulation, you can use the Principal Triangulation image from Wikipedia, and the Lancashire Triangulation map from the map library to help illustrate this. Show them how to:
- set up the tripod
- mount the automatic level (don't level the automatic level, as we are using it as a theodolite)
- use a mirror compass
- set the automatic level using the compass (take a bearing to an identifiable object with the compass, then sight to the same thing using the level and then rotate the bezel/level to set it)
- use the GPS to work out where they are, understand that they need to add a '3' and a '5' to the easting and northing values respectively
- use the app to get a location
Use the highest point on the white building to get a direction - there are several other buildings in view (including other farms and the Newlands church) for them to practice.
Walk them on to the foot bridge, and get them to work out where they are, including orientating the map. Explain about coordinates and how to locate points on the map (which has a 100m grid). While walking, you can chat about the industries that have affected the valley - mining (copper & lead, German miners, Cumberland sausage, graphite in Borrowdale; sheep farming, Herdwick sheep; tourism).
Explain the task (to plot the course of the stream, they must make a plan, go and do it, and be back at the footbridge with 30 mins for debrief and walk back). Split them into two 'teams' if kit allows and there are enough students. Note that the students can only access the river bank on the East side, so tell them to map this, and to be careful around the large river cliff. They must have a clear plan, including how far should the staff(s) move each time? (100m = c. 70 double paces...) and who is doing which job (operating level, staff, app, marking the result onto the map, radio controller).
They should set up their 'base stations' each side of the spoil heap (so they can’t see each other) - though the further apart the better - this is important - success is basically directly proportional upon the area of the triangle so make sure that the baseline is nice and wide (at least the full width of the spoil tip)! Walk straight up to the slag, don't loop round the path. Make sure that you are up there to make sure that they do it right - if they mess up the orientation, then the results will be miles off!
When they return, compare their effort to the real map; you can then have a discussion about precision and uncertainty and how these things build up in field work, as well as about how well they worked as a team (invariably they will have set off before really agreeing on a proper plan). Then ask them to measure it (using compass string and grid squares) - lead into a discussion about the Coastline Paradox, and the fact that you cannot really measure the 'length' of a river - it is a function of the scale (in this case, how big the gaps between readings were).
Leave 30 mins for the debrief (comparison & coastline paradox chat) and to walk back to the van.
Equipment
Students (per team, comprising two 'bases', one or two staffs and a controller):
- Mirror Compass x 2
- Surveying Staff x 1-2
- Automatic level & Tripod x 2
- Walkie Talkie x 4
- GPS receiver x 2
- Android mobile phone with waterproof case x 1 (with the project app (to handle the triangulation maths)
- Pencil x 1 (one each)
- A4 Clip board x 1 (one each)
- Student Handout x 1
Staff require:
- Staff Handout x 1
- Principal Triangulation image from Wikipedia
- Lancashire Triangulation map (can just excerpt the triangulation bit)
