Now at the end of March 2013, after our trip aboard Kingswear Castle we've walked along the quayside towards the Lower Ferry and turned off into Hauley Road. At its end facing us is - or rather was - the Harbour Bookshop. We can see pictures in the window. Looks like a gallery. We're closer now. It's the Whistlefish Gallery. Blame the Internet. The plaque is still there. And there is another one close by literally a few steps away. It is on a wall, and yes I'm back eulogising on Newcomen. When he invented his steam engine it was the size of a house. It took the likes of Watt and Trevithick to develop it into something more efficient and portable. They advanced the idea, but it was Newcomen who invented it right here, and we are standing where his house stood. A plaque is in a retaining wall between Higher and Lower Street. The house - demolished in 1864, was where he spent a decade or so working out his idea with his assistant John Calley.

We're standing in front of this small insignificant plaque now. Newcomen was a devout Baptist, christened at the nearby St Saviours Church on 24 February 1663. He rented the house in 1707 and used part of it as a place of worship for his Baptist friends. I imagine him praying often for help with his invention, while he bought and sold ironmongery, locks nails etc., and traded in iron, some of which he bought from the Foley Iron Masters in Worcestershire. And all the while the idea for his fire engine took shape. I guess he read his Bible regularly, especially Matthew 7.7. 'Ask and it shall be given you, seek and ye shall find, knock and it shall be opened to you.' I wonder if he ever thought his engine would evolve one day to take the place of oars and sails on his river nearby. I am saddened by the plaque. It seems so inferior to the invention but at least it records the event. "Here stood the workshop of Thomas Newcomen who first drove a piston through the agency of steam and created the world's first steam engine"

We turn back towards the bookshop where I bought Richard Clammer's and Alan Kittridge's book on Dart Paddle Steamers. Through that book I learned about Compton Castle, and remembered her when I first saw her at Truro. It seems right that these plaques stand in sight of each other. And it feels right that Kingswear Castle is back home on the Dart.

We were last here in 2012 when I was surprised the Harbour Bookshop had closed. The shop fitters were at work when we passed by that year. I asked the chap in the cream T-shirt what it would reopen as. "No one knows" he replied. It had closed in September 2011.The owners, blamed rising rents and increased competition from online booksellers and supermarkets.

Christopher Milne set up the bookshop in 1951 and ran it until 1983 when he retired. Andrea Saunders, who was employed in the shop by Milne, said he used to hide from people who wanted to see the "Original Christopher Robin. Americans used to come - obviously they'd heard the Winnie the Pooh stories - and they were very keen to meet Christopher Robin. They used to come in and say: 'Is Christopher Robin here today?' and Christopher would scuttle away and say 'I'm not in, I'm not in'. He would hide away upstairs and we'd have to say we were sorry but he wasn't working."

But he didn't hide from Jean.

I noticed the plaque was still on the side wall so at least the Harbour Bookshop won't be just a memory. Well that's what I thought in 2012.