Question

Construct a linear scale to show miles and furlongs when the R.F. is `1/(50,000)`.

Answer 1

Given: R.F. = `1/(50,000)`

1 mile = 63,360 inches

1 mile = 8 furlongs

Let the length of the scale be 6 inches.

1" on the map = 50,000 inches on the ground.

`(50,000)/(63,360  "inches/mile") = 0.788` miles (approx.)

So,

6 inches on the map = 6 × 0.788 = 4.73 miles (approx.)

To keep it clean, let’s take it as 4 miles on the ground.

Drawing the scale:

Draw a 6 inches long line.

Divide it into 4 primary divisions (each = 1 mile = 8 furlongs).

Subdivide the first primary division into 4 secondary divisions, each representing 2 furlongs.

Labelling:

Label 0, 1, 2, 3, 4 miles to the right of 0.

Label 2, 4, 6, 8 furlongs to the left of 0.

Title the scale: "R.F. = 1 : 50,000"