Francis Egerton, 3rd Duke of Bridgewater, owned extensive coal mines near Manchester. He spent a fortune operating them and a canal to carry the coal to Manchester and Liverpool. He noticed that his workers ceased working the moment the bell struck twelve times at twelve o'clock, which was lunch time. They, however, were slow in returning to work at one o'clock. The excuse was that they did not hear the clock strike just once. The Duke then had the clock made to strike thirteen times at one o'clock, so that the men could no longer use the excuse that they did not hear it. Mark Twain is claimed to have said: "The thirteenth stroke of the clock is not only false of itself, but casts grave doubt on the credibility of the preceding twelve". The idea of a clock striking thirteen times has shown up many times in literature. The most famous is the first line in George Orwell’s "Nineteen Eighty-Four" when it starts with, "It was a bright cold day in April, and the clocks were striking thirteen". The famous children's book "Tom's Midnight Garden" by Philippa Pearce speaks of this phenomenon when it says "When Tom hears old Mrs Bartholomew's grandfather clock in the hall striking thirteen, he goes to investigate". Thomas Hardy's "Far from the Madding Crowd" (1874) 'This supreme instance of Troy's goodness fell upon Gabriel's ears like the thirteenth stroke of a crazy clock' (Chapter XXIX, Particulars of a twilight walk)  Most countries around the world use the 24-hour system for technical purposes and in documents such as timetables; the United States is an exception, although US military bodies do use the 24-hour clock. Most digital clocks can be set to show the time as, for example, 13:00, and this is frequently done. However, typical analogue clock design conserves the 12-hour system, and so does everyday speech. In English, in fact, the term "13 o'clock" is not used; when referring to something like a timetable that uses the 24-hour clock, or in a military context, one would say "Thirteen hundred hours". In other European languages, the terms equivalent to "13 o'clock" are used, e.g. in French one usually refers to 1pm as ""treize heures"", though it would not be incorrect to say ""une heure de l'après-midi"", the equivalent of "1pm".