From the book The Story of the Aleph Beth, by David Diringer. (Pretty boring book, but meh...)
ENGLISH SPELLING "This brings us to the problem of phonetic spelling and the much-discussed necessity of spelling reform. Very few alphabets are what we may call perfect; such an alphabet would imply the accurate rendering of all speech-sounds: each sound would be represented by a single, constant symbol, and not more than one sound by the same symbol. In English, for instance, the number of the ancient Roman letters was from the beginning insufficient to express with accuracy wlal the sounds (there are no single letters to represent the sounds th, sh, ch), while several letters are redundant (a and c when representing the sound k). As a result, while English is probably the richest and most colorful of all modern languages, English spelling differs so much from pronunciation that in many words it is almost an arbitrary symbolism. What better example of the English spelling-problem can be given than the following sentence containing ten different pronunciations of ough ("uff", "oe", "ow", "off", "up", "oo", "ock", "a", "aw", "o"): "The rough-headed dough-face ploughman went coughing and hicoughing through the village after the houghing the thoroughbred which he had bought for his brougham.""