Suddenly, spring.

April has flown by, with family visiting in the first half, and a trip to Washington DC and Pennsylvania in the second half. Amongst other trips, we enjoyed Boston harbour and the USS Constitution on a cold but sunny day.The Constitution remains a US Navy ship with a naval crew, and visitors are told lots of stories of heroism against the dastardly British in the 1812 war (incidentally started by the USA...). I asked one of the crew how much of the original timber remains - apparently only about 10%, mostly the keel.

USS Constitution, still in  full sailing condition

Jonathan enjoying the best harbour tour - commuter ferries at $3 a trip

After Caroline and Jonathan left to return home I set off for DC, where I had a series of meetings and some time to see the sights in the remarkably compact heart of the city. Everything familiar from tv and movies is within half an hour's walk, although the security was intense in the aftermath of the Boston marathon bombing.  I received an email from Harvard, cancelling a conference due to take place on the day of the manhunt for the bombers which shut down Boston. The title of the conference was 'Confronting Evil',but with a certain black irony the organisers had to do rather the opposite.

The Washington Monument under repair after earthquake damage

The Smithsonian museums are wonderful, numerous and free. I only had time to visit the Air and Space museum, where they have the original Wright Flyer, the first powered aircraft on display. I was also struck by their descriptions of Zeppelin bombing raids on London in WWI - not least because my grandmother had described to me how her family would take cover under the stairs from the same air raids.

 Some Secret Service officers get to wear shorts...

Lots of layers of security around a certain famous residence

From the imperial splendours of DC I drove west into the mountains, to Harpers Ferry, where the Potomac and Shenandoah rivers meet and John Brown arguably fired the first shots of the Civil War. Close at hand was the Antietam Battlefield, where huge casualties were inflicted on both sides for little apparent purpose.

The Potomac from the Harpers Ferry Youth Hostel in spring sunshine

I took the weekend off and biked around the area, stopping at the wonderful Nutter's Ice Cream in Sharpsburg, and climbing up from Cumberland on the GAP rail trail to the Eastern Continental divide, separating waters that flow to the Atlantic and the Gulf of Mexico.

Nutter's Ice Cream in Sharpsburg

The Eastern Continental divide at about 2800' asl near Cumberland, Maryland

 From Cumberland I drove north through the endless suburbs of Pittsburgh to Meadville in NW Pennsylvania. In fact, I wasn't far from Lake Erie, and an alternative and rather easier ride would have taken me to the continental divide just north of Meadville where the giant moraines left by the Laurentian glaciers form a range of low hills as the watershed. These hills are essentially the same structures as the Cape Cod and Martha's Vineyard far to the east - glacial debris forming raised topography. A historical plaque in front of Meadville's courthouse describes it as 'The cradle of the oil and zipper industries' - the oil era essentially started near here where the discovery of a natural oil seep led to industrial scale extraction, drilling and, well, the modern world. Similarly, civilization has been forever altered by the invention of the zipper, so we should be doubly grateful to Meadville. It's a lovely college town as well as a mostly post-industrial centre, and I was welcomed at the Allegheny College for a couple of days of discussions and lectures. Like much of Pennsylvania, Meadville is divided politically between the Democratic, urban, college-related population and the Republican rural surroundings, but there are also significant numbers of far-right survivalist types, preparing for the the takeover by the UN. Bizarrely, the farmer's market here spans the entire political divide with hippie artisanal cheesemakers and organic farmers rubbing shoulders with survivalist types wanting to live off the land and be self-reliant under some future apocalyptic scenario. It sounds like a suitable setting for a modern retelling of Romeo and Juliet...

 A long drive across Pennsylvania saw me picking up some trees from a nursery for a friend in Petersham. Having thought and talked a lot about moving new trees species and provenances to increase the chances of retaining some big old trees in coming centuries, the impending loss of ash trees around Eric's house gave us a chance to explore the practical choices we might make. So I gathered up a dozen oaks and hickories from more southerly origins near Philadelphia and we planted them on a sunny Friday afternoon at his house, and wished them a healthy next 300 years.