Can you guess what it is yet?

[alicat]

Oh no, I'll put my thinking cap on!

 

[jonny jeez]

Oh no, I'll put my thinking cap on!

Is it a thinking cap?

 

[Pale Rider]

Congratulations!
It's a map measurer, still in use, too...

View attachment 343047

This might be a daft question, but how do you know how far you've tracked the wheel across the map?

Most similar tools I've seen have a dial.

 

[alicat]

Here you go

 

[Fenrider]

This might be a daft question, but how do you know how far you've tracked the wheel across the map?

Most similar tools I've seen have a dial.

View attachment 343060

You set the knurled wheel to zero by winding it along he screw thread to one end of its travel. You then run the wheel along the route on the map you wish to measure (following all the twists and turns in the road). As the wheel rolls along the road, it travels along the screwthread. You then measure the distance the wheel has travelled by running it backwards along the scale at the bottom of the map.
Simples!

 

[Supersuperleeds]

You set the knurled wheel to zero by winding it along he screw thread to one end of its travel. You then run the wheel along the route on the map you wish to measure (following all the twists and turns in the road). As the wheel rolls along the road, it travels along the screwthread. You then measure the distance the wheel has travelled by running it backwards along the scale at the bottom of the map.
Simples!
View attachment 343065

When I was in the cadets we used a piece of string to measure the distance of our routes.

 

[Pale Rider]

When I was in the cadets we used a piece of string to measure the distance of our routes.

At school we used the edge of a piece of foolscap and a pencil, rotating the paper under the pencil to follow the bends in the road.

 

[Supersuperleeds]

At school we used the edge of a piece of foolscap and a pencil, rotating the paper under the pencil to follow the bends in the road.

Thinking about it, used do that as well. Those where the days, used to love planning routes with a paper map.

 

[Fenrider]

When I was in the cadets we used a piece of string to measure the distance of our routes.

So in fact this device is just a sophisticated piece of string....

 

[alicat]

Flippy up leg on a keyboard?

No

 

[Fenrider]

At school we used the edge of a piece of foolscap and a pencil, rotating the paper under the pencil to follow the bends in the road.

Me too. It certainly taught me about map scales.

 

[Fenrider]

Sorry Alicat, back to your challenge...
Is it a fold-up leg of a picnic table?

 

[alicat]

Is it a fold-up leg of a picnic table?

No

I enjoyed the chat about map measurers, btw.

 

[EltonFrog]

Some kind of catch or latch in a car boot?

 

[alicat]

Some kind of catch or latch in a car boot?

No, sorry.