mercury pressure gauges
... that mercury pressure gauges as tall as 23 metres (75 ft) have been built to measure very high pressures?
... that <b id="mwBA8"><a href="./Mercury_pressure_gauge" id="mwBBA" rel="mw:WikiLink" title="Mercury pressure gauge">mercury pressure gauges</a></b> as tall as <span about="#mwt59" data-mw='{"parts":[{"template":{"target":{"wt":"convert","href":"./Template:Convert"},"params":{"1":{"wt":"23"},"2":{"wt":"m"}},"i":0}}]}' id="mwBBE" typeof="mw:Transclusion">23 metres (75</span><span about="#mwt59" typeof="mw:Entity"> </span><span about="#mwt59">ft)</span> have been built to measure very high pressures?