1. A horizontal dial
    Geometrical construction  Calculations  Definitions 

2. Timeline

3. Geometrical markup technique

4. Notable examples

5. References

6. Bibliography

A London dial in the broadest sense can mean any sundial that is set for 51°30′ N, but more specifically refers to a engraved brass horizontal sundial with a distinctive design.

London dials were originally engraved by scientific instrument makers. The trade was heavily protected by the system of craft guilds.