<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">engineer&apos;s blue</topic></authority><related type="broader"><topic>Prussian blue</topic></related><variant type="other"><topic>blue, engineer&apos;s</topic></variant> <note xml:lang="en"><![CDATA[ An oily film of Prussian blue pigment formerly used in machine making; it was placed on machine fittings, then the parts were rubbed together; the removal of the pigment indicated the position of high spots or rubbing between the two surfaces. ]]></note></mads>