If you are a school pupil, even your literature will be subject to tampering. Here is an original Passage from King Solomon's Mines, by H. Rider Haggard, describing the warriors of Kukuanaland.
"They were all men of mature age, mostly veterans of about forty, and not one of them was under six feet in height, whilst many stood six feet three or four. They wore upon their heads heavy black plumes of Sakaboola feathers, like those which adorned our guides. About their waists and beneath the right knees were bound circlets of white ox tails, while in their left hands they carried round shields measuring about twenty inches across".
And here is the version of the same passage as printed in the Collins English Library level four school reader:
"Not one was less than a hundred and eighty-five centimetres in height. On their heads they wore the long, heavy black plumes of the Sakaboola bird. Around their middles, and beneath their right knees, were tied white oxtails.
In their left hands they carried round flat shields, about fifty centimetres across."
It should be pointed out that the original passage given first is also taken from a school reader - for the same age group - but one which was in use at least thirty years ago. Apart from the crass, inexcusable 'metrication', the difference in expected reading standards is quite revealing, is it not?
It may be appropriate to conclude these comments with a quotation from Richard Ingrams in the Sunday Telegraph (writing about another matter):
"What usually happens in these circumstances, when an establishment wishes to impose something which they know is unpopular and unwanted, like decimal currency or metric weights and measures, is that it is filtered slowly into the system in the hope that no-one will notice until it is too late."