What Is A Lighthouse?

Many of the published definitions for the term "lighthouse" are inadequate in today's context.

A precise definition of a lighthouse is:

"A fully or partially enclosed built structure bearing a light that is used as a navigational aid and that is capable of admitting at least one person to operate or maintain the light entirely from within."

This is represented in the diagram shown in Figure 1

This work has also been published in:

Ken Trethewey, "What Is A Lighthouse? A Modern Definition". World Lighthouse Society Magazine, 1st Quarter 2013, Volume 11, Issue 1, p5-14 available here.

In this paper the author describes a precise set of definitions suitable for use in pharology. In particular we learn how to distinguish various kinds of navigational aids. The complete paper is presented in a more convenient format in the following sections.