Steam-powered compressor, Brotherhood, London, 1888 From the Laboratory of Physics of the University of Leiden. Inv V07772

The Leiden physicist Heike Kamerlingh Onnes was a real fixer. For example, around 1900 he needed compressors, but the laboratory had no money to buy any. Now the Dutch navy used compressors for filling torpedoes with compressed air, and since it was peacetime they were prepared to lend them to Kamerlingh Onnes. However, one of the conditions required Kamerlingh Onnes to return the pump if there were a threat of war. That promise did not prevent Onnes from adapting the compressors immediately after their arrival. An improvement, Kamerlingh Onnes would undoubtedly have called the changes. But whether they were also improvements for the navy was never put to the test. The Netherlands did not participate in the following war, and the navy never asked its machines back.