To use an illustration. When some Oxford Undergraduates rowed in a four-oar boat across the straits of Dover, it was stated in the Press reports that one of them caught a crab. The London correspondent of the Cologne Gazette took this literally, and faithfully reported to his paper, that a crab had got entangled in the oar of one of the rowers. If a man who has been living for years in the midst of London is capable of such a ludicrous blunder as soon as he comes across the technical terms of an art unknown to him. what must we expect from a man who with a passable knowledge of mere book-German, undertakes to translate the most untranslatable of German prose writers? And indeed we shall see that Mr. Broadhouse is an excellent hand at catching crabs. But there is something more required. Marx is one of the most vigorous and concise writers of the age. To render him adequately, a man must be a master, not only of German, but of English too. Mr. Broadhouse, however, though evidently a man of respectable journalistic accomplishments, commands but that limited range of English used by and for conventional literary respectability. Here he moves with ease; but this sort of English is not a language into which Das Kapital can ever be translated. Powerful German requires powerful English to render it; the best resources of the language have to be drawn upon; new-coined German terms require the coining of corresponding new terms in English. But as soon as Mr. Broadhouse is faced by such a difficulty, not only his resources fail him, but also his courage. The slightest extension of his limited stock-in-trade, the slightest innovation upon the conventional English of everyday literature frightens him, and rather than risk such a heresy, he renders the difficult German word by a more or less indefinite term which does not grate upon his ear but obscures the meaning of the author; or, worse still, he translates it, as it recurs, by a whole series of different terms, forgetting that a technical term has to be rendered always by one and the same equivalent. See the whole article.
How Not To Translate Marx by Frederick Engels 1885