For many young men miles away from home, getting a letter while serving on the frontline during the Second World War was a moment of joy.
Getting a parcel or postcard from England could make them forget for a minute the frightening and lonely experience war must have been.
So in March 1941 staff and children from Reddiford School in Pinner decided they would start writing to officers on board HMS Cotswold - a battleship commanded by Captain Peter Dickens, great-grandson of Charles Dickens.
They would pen their own accounts of wartime life and send them to men on board the ship - to cheer them up and remind them of life back home.
The collection, which goes on display at Pinner Library next month, is a real insight into the thoughts and fears of Pinner children during the Second World War.
Joanne Verden, who still lives in Pinner, was one of the children at Reddiford School who started writing letters when she was just 10 years old.
The former pupil - now in her 70s - returned to the school last week to talk about the letters, and was delighted to meet children from the school today.
She said: "During the war our teach-ers thought it would be a good idea to cheer up sailors on board HMS Cotswold.
"We wrote about what we had been doing at school and how we were dealing with the pressures of war.
"We would also knit them socks and mittens to keep them warm.
"Writing the letters was particularly poignant for me because I had an older brother in the Royal Navy on board the Battleship Ramilles.
"After school I would sit and listen to the six o'clock news on the radio to see how many ships had sunk and find out if my brother's had gone down."
The collection is now in the care of Marion Lloyd, daughter of the ship's captain.
Mrs Lloyd, who lives in Hammersmith, got in contact with the school after discovering the bundles of letters her mother had looked after.
She said: "My father served on the ship and was in charge of distributing letters to other officers. It was really important for morale and sailors enjoyed writing back.
"It was also my dad's job to censor letters to make sure officers weren't giving away secrets about where they were and what they were doing."
After the war, Captain Dickens made a file with more than 50 letters and kept them until he died in 1987. His daughter is now hoping to track down the writers who may still live near the school in Cecil Park, Pinner.
She said: "This is a brilliant piece of social history and really captures the time these children were living in.
"In the middle of shooting down German fighter planes the sailors liked to remember a normal way of life. Writing to the children really boosted their morale.
"Some of the people who wrote these letters would now be in their seventies and may possibly live locally. It would be brilliant to track them down and reunite them with the letters they wrote."
Matthew Huggett, a year five pupil at the school today, visited the exhibition last week and was fascinated to meet letter writer Joanne Verden, who was tracked down by the school through The Pinner Local History Society.
The 10-year-old, who is studying the Second World War, said: "It is really interesting to see how different the lives of children were in the 1940s.
"We are learning about the Second World War, so it was great to meet someone who actually lived during the war and went to my school. I think it was a good idea to help make the sailors feel better while they were away at war."
Johanna Foley, head of humanities at the school, helped organise the exhibition and is looking forward to reuniting writers with their letters. She said: "We are already working out if families still live in the area through records, which is really fascinating.
"It is also great for the pupils to speak to people who were at the school during the war and to hear their accounts. It makes learning about history so much more exciting."
In this digital age there is less and less letter writing, but we should always remember it was an important way of cheering up the brave men who went to fight for this country in the Second World War. The letters from Reddiford School pupils stand as a good example of that.
* The exhibition will be at Pinner Library in Marsh Road, Pinner between July 8 and July 28. For more information call the library 020 8866 7827.
* We are interested to hear from anyone who was at Reddiford School in the 1940s and wrote letters to those on board HMS Cotswold. If you were a pupil at the school, or know someone who was, please contact Tara Brady on 020 8956 8195.
* Have an interesting story to tell? Why not contact us here