The Scaffold | Population | Time for bed | Babies in the Commons | Mask costs

In 1968, watching the Eamonn Andrews show on Christmas Eve, I can remember asking my dad what “efficacious” meant when the Scaffold sang Lily the Pink (Our song was Christmas No 1 and we wanted to watch it on TV. So we knocked on a stranger’s door, 24 December). I don’t think I heard the word again until December 2020, when scientists started discussing the efficacy of Covid vaccines. As vaccinations continue over the festive period, I hope we can all “drink a drink” to toast our NHS workers for indeed being “the saviours of the human race”. Andrew Keeley Warrington, Cheshire

I once asked the geography professor Danny Dorling, someone who knows far more about the UK’s population than me, how many people he thought the UK could accommodate before being full. His immediate answer was 100 million. Your correspondents (Letters, 27 December) highlight the need for sufficient resources to support our population, but provision of them is a matter of politics, not land area. Mark Walford London

The anthropologist Audrey Richards was famed in Uganda in the 1950s for ejecting guests at 10pm sharp (Letters, 28 December). She wore a nightie under her clothes and simply undressed as the clock struck. Jenny Swann Beeston, Nottinghamshire

You report the Speaker’s ruling allowing MPs to bring their babies into the Commons during debates (28 December), which sounds like common sense to me. But the real breakthrough will come when a father brings his baby in with him. Rev Geoffrey Lang London

A very interesting article by Aaron Collins on masks (Some Covid masks are better than others. I know – I’m the Mask Nerd, 27 December), but the casual reference to his recommended mask costing “less than a pound” makes me wonder how a family on universal credit can have a hope in hell of providing these for its members? Mary Moore Somerton, Somerset

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