Our efforts to record Tiananmen atrocity | Tiananmen Square protests 1989

Your article (‘Every year I get new pictures’: the fight to preserve the memory of Tiananmen, 4 June) did not mention the Tiananmen archive held in the British Library, which includes documents and photos, and was established in June 1989. On the evening of 3 June, before any shooting had started, a large group of concerned sinologists met in my house, very worried about what was going to happen. One of our decisions that evening was to collect everything we could about Tiananmen and events there.
Frances Wood
London

In attempting to resist Jonathan Liew’s suggestion that people come off X, Matt Watkinson instead makes Liew’s argument for him (Letters, 3 June). He says he remains on X because all major companies “know they can reach us swiftly”. Exactly. So if you went to an alternative app, presumably the companies would follow.
Lesley Taylor
Cambridge

Surely the best Speke joke (Letters, 4 June) is the one about the man at the railway station who asks: “Is this train going to Speke?” To which the guard replies: “Well, I’ve been working on it for 10 years, and it hasn’t said anything yet.”
Heather Cooper
Cowes, Isle of Wight

JD Vance is right about the problems caused by “the mass invasion of migrants” (Report, 5 June). Look at the US and ask Native Americans how they feel.
Dee Northover
Bristol

Re alternative number bases (Letters, 7 June), there are 10 types of people: those who understand binary, and those who don’t.
Eric Sharp
Newcastle upon Tyne