On Thursday we took a 4-hour train ride back from Edinburgh to London; on Saturday I took a plane back from London to Montreal, and today I'll take a train from Montreal to Kingston. So I spent a day and two partial days in London as the last couple of vacation days. There is a lot to see in London, plenty for a month (or a year!), so we had to pick just a couple of highlights
On Thursday it was around 4:30 or 5 when we got settled in our hotel near the Bayswater tube stop in Kensington, so we took a walk around the Kensington Gardens park. We saw the outside of Kensington Palace; it's open to the public but was closing by the time we got there. The sun was low over the building at the time, so I don't have a good photograph.
Of the many things we could have done on Friday, I had to pick two, and the one I most wanted was to see Babbage's Difference Engine, one of the oldest computing machines (the oldest analog one being the Antikythera device), and straddle the Prime Meridian in Greenwich. The piece of the real difference engine is housed in the Science Museum's Making the Modern World exhibit, but there is also a complete model built in 1991, located on the second floor standing alone at the top of the stairs. The conclusion of the 1991 project was that building the Difference Engine was well within the capabilities of Victorian engineering, and the project's failure had much more to do with financing, politics, and Babbage's difficult personality. If it had succeeded, and managed to compute and print the kinds of enormously valuable tables it was meant for, it's conceivable that the British Government might have been willing to fund the Analytical Engine, which would have been the first programmable digital computer, and the world would be a very different place.
Next to Difference Engine #2 (the modern implementation) was the clockwork museum, formerly housed in the much less prominent building of the very old clockworker's guild. I learned more about the creation in Britain of the first maritime clocks, which let navigators compute longitude quickly and accurately by comparing local time with a fixed reference point -- the Prime Meridian in Greenwich. That was my second-highest priority for Thursday.
Greenwich is about 40 minutes by Underground and Docklands Light Rail from South Kensington (which has several museums) so there-and-back took a noticeable bite out of our day. Nevertheless I got my I-was-here photo:
The observatory includes one of these:
The museum also includes more details on the creation of the first maritime chronometers, and their evolution after that. John Hamilton won a prize for making a series of four proof-of-concept implementations that were tested out by the Royal Navy, but a lot of other people contributed refinements that made them better and more affordable.
On the waterfront near the DLR stop is Cutty Sark, one of the last and fastest tea clippers. We only stopped long enough for a couple of photographs:
On Saturday we could only fit in one trip, so I chose Tower Bridge.