Today the science of navigation seems simple. All one has to do is push a nob on a black box machine to discover where one is on the globe to within an accuracy of 10 metres. But compare this with the same problem, finding one's exact location, with the tools and technology three hundred years ago. In 1714 it was impossible at times to give a determination of location to an accuracy better than of tens of miles. When at sea, at night, in storm and close to a lee shore it could easily be a matter of life and death, upon which lives and cargo depended. The English recognized the need for improvement in the science of naval navigation. To that end an Act of Parliment was signed by Queen Anne for a practicable solution to the problems facing the Royal Navy. In 2000 there was produced a tele-play entitled Longitude. With very high production values, galaxies of "stars", and an ample budget it is, in my humble opinion, well worth the three hours to view it.