The compass platform was used a minimum of 48 times every day. The two junior officers of the watch had to coordinate their efforts to "steady the ship" by the standard compass on the platform and make sure it was steering the correct course by the steering compass in the wheelhouse. This sounds odd, but it's common sense.
A ship can only have one "standard" compass (think of "gold standard," the compass by which all others aboard are judged.) In computing a course, the deviation used was for the standard compass in the platform. The ship was then steered by bell commands from the platform to the wheelhouse until it was on course. The reading of the steering compass was noted and that was used to steer the ship.
Every 30 minutes it was required by IMM/White Star regulations for the ship to be steadied on course again by standard compass so that it was certain the steering compass had not strayed.
In addition, the standard compass had a special sighting ring for taking star azimuths. These allowed the accuracy of the standard compass to be checked using celestial observations.
All-in-all, the two junior officers of the watch must have gotten a bit tired of this drill. But, the constant comparison and checking of the steering compass remained part of daily life well into the modern era when electronic navigation finally became a reality.
Of particular note in the Titanic story is the location of the standard compass. The industry practice was to place it atop the wheelhouse where there could be direct 2-way voice communications with the bridge. Some ships even had speaking tubes or small hatches in the wheelhouse roofs for the purpose. Not Titanic nor most of the White Star ships. For some reason, WSL standard compasses were mounted amidships. This probably reduced the magnetic effect on the standard compass from the ship's hull. But, it created real communications problems for the officers. On Titanic there was only a one-way bell pull from the platform to the wheelhouse.
-- David G. Brown