Precisely How Far?

Last week we had a look at map scale and how we can use it to work out how far it is between 2 places.  But if the road isn’t straight, measuring the direct distance “as the crow flies” is not so helpful.

To take into account the twists and turns in the road you can use something flexible, like string, to follow the route. 

Lay the string along the route, then take hold of it at the starting point (A) and the destination (B), pick it up and pull it straight.  You can then lay the string next to the scale line to read the distance between the two points.

You can also use a piece of paper, as we did when we measured river sinuosity last year.

Line the paper up with the first section of the route and make a mark at the start (A) and another where the line you want to follow starts to move away from the edge of the paper.

With the pen on this point, swivel the paper round a little to line up the next section and repeat all the way along to the destination (B).

Then move your paper and line it up with the map’s scale line, as we did last week.