While in Greenwich I stopped over at the Royal Observatory and was able to see the famous Harrison clocks built by John Harrison as part of the race to find longitude. I had read the book Longitude by Dava Sobel as one of my book review choices. It was interesting to actually see the clocks that I had read about. The about image shows H4, the fourth of Harrison's clocks and the most successful at keeping time. The other clock on display looks like a complex steam engine with so many intricate parts (something like 700 individual hand crafted parts on one of the clocks) it's amazing to think that they were built in the 18th century. The chronometers that came of use because of Harrisons efforts allowed for the Royal Navy to use complex and accurate navigational techniques, certainly aiding in the rise of the British Empire. The main problem in determing longitude for all those years was an inability to keep accurate time, which have allowed the charting of location. Harrison's clocks solved that problem.