- Difficulty:

- Terrain:

Size: (micro)

#### Watch

How Geocaching Works

**Please note**Use of geocaching.com services is subject to the terms and conditions in our disclaimer.

### Geocache Description:

Needless to say, this cache is not at the published location.

The roundel is a globally recognised symbol for the London Underground, it has previously been known as the Bullseye, and the Bar and Circle.

Transport for London continue to use the roundel as the identification of both TfL and its services.

The Roundel consists of an annulus centrally bisected by a horizontal bar which protrudes an equal distance from each side.

**Notes:**

Calculate to 3 decimal places

Midway between Points F and A, Point J is the centre point of the annulus and the horizontal bar

The radius of the inner circle = line BJ

The radius of the outer circle = line HJ

The length of the bar = 2 x line FD

The height of the bar = line FA

Calculate XXXXX = Area of one face of the Roundel

The Westing = W000° XX.XXX (use the integer value of X)

Depth of Roundel = Y where:

if the integer value of X is even: then Y= 7.1186

if the integer value of X is odd: then Y= 7.117

NB: This will hopefully catch any rounding differences,

I have tried manual calculation and Excel with precision to 3DP.

Calculate ZZZZZ = Volume of Roundel (X x Y)

The Northing = N51° ZZ.ZZZ (use the integer value of Z)

**
Additional Hints**
(Decrypt)

Decryption Key

A|B|C|D|E|F|G|H|I|J|K|L|M

-------------------------

N|O|P|Q|R|S|T|U|V|W|X|Y|Z