One extra Ut4 tuning-fork and one Ut4 + four vibrations, with resonance-boxes. By Koenig, Paris Note that the photograph shows three tuning forks, the third one probably belonging to another to <link ref="tec2974">another set of tuning forks</link> on the same photograph. See color photographs of tuning forks in the Harvard Collection of Historical Scientific Instruments: <link href='http://dssmhi1.fas.harvard.edu/emuseumdev/code/emuseum.asp?rawsearch=Number%2F%2C%2Fis%2F%2C%2FWJ0009%2F%2C%2F0%2F%2C%2F0'>UT 4</link>, <link href="http://dssmhi1.fas.harvard.edu/emuseumdev/code/emuseum.asp?rawsearch=Number%2F%2C%2Fis%2F%2C%2F1997-1-1040%2F%2C%2F0%2F%2C%2F0">UT 2</link> and <link href="http://dssmhi1.fas.harvard.edu/emuseumdev/code/emuseum.asp?rawsearch=Number%2F%2C%2Fis%2F%2C%2FWJ0008%2F%2C%2F0%2F%2C%2F0">UT 4</link>. One extra Ut4 tuning-fork and one Ut4 + four vibrations, with resonance-boxes. By Koenig, Paris

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