| http://www.w3.org/ns/prov#value | - In Sweden we had it at twenty-five to start with, and in many other countries we had a variety of frequencies.<br> +<p>But when people began to combine their systems we had to join the lines, and fifty hertz was considered okay in Europe, except for railways, where we used to have a lower frequency, sixteen and two-thirds, which is one-third of fifty.
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