One of the most interesting aspects of photographs is that they capture an instant in time and fix it for eternity. I am not talking about the carefully composed pictures of grand old structures - such as the west front of York Minster illustrated above - but the unpretentious snap that shows grandad with his false teeth falling out or baby Stanley pulling a silly face. But what some vintage postcards miss on one side, they more than adequately make up for on the reverse side. The card comes from Walter and was sent to his cousin who was living in Hull. I have no more of an idea who either of them are than I have the story of how the card made its way from Miss Clarkson's sideboard to a 50p remainders box in an old junk shop. But we have that frozen moment in time : it is the morning of the 18th June 1915. In France, the Second Battle of Artois was in full swing, but in York, Walter was on his way to Ripon. Perhaps he was moving house, perhaps he was part of a massive troop movement in anticipation of leaving for the mud of Flanders. Who knows. Our frozen moment in time just sees him taking the time to buy a picture postcard and pen a swift message to his cousin in Hull. It was a text message of the time; a SMS that has survived down the years. It is rather sad for the digital archaeologists of the future that few of today's text messages will survive in the same way.