Sir: Jonathan Glancey is quite right ("Qwerty lovers do it manually", 28 August) to describe certain typewriters as design classics. I too keep my Olivetti portable as a well-designed object, but I would never dream of using it, for, like the pen, even the pencil, the typewriter is far too definite.
Once the words are on paper you are very stuck with them. On the computer screen, by contrast, words are merely lights, you can delete them, substitute new ones, shuffle them around, individually, as whole sentences, even whole paragraphs. As the composer Giles Swayne says of Sibelius software for composers ("Sibelius scores with the keyboard composers", 28 August), what you have is "more like a sculpture. You have an object which you can shape and adapt."
Which means that whatever need, from the absolute precision of scientific language to the subtle nuances of poetry, you can get exactly the right word in exactly the right place.
As for PG Tips and toast and Marmite, as sources, presumably, for inspiration, the words on the screen float even more freely after a gin & tonic.