Glossary · Regulation
Regulator (index)
A sliding lever that effectively lengthens or shortens the active portion of the hairspring to adjust rate.
Explanation
The regulator (index) is the lever, usually marked fast/slow or advance/retard, whose pins embrace the hairspring near its stud. Moving it changes the spring's effective length and so the rate. Moving the regulator disturbs the hairspring's breathing, so fine watches are adjusted by screws on the balance ('free-sprung') with no regulator at all.
In the object catalogue
Catalogued objects whose own source record mentions “Regulator (index)”. The quoted line shows where; it is the seller’s or museum’s wording, not independent verification.
Movement
English fusee detached lever pocket watch movement by John Harrison, Liverpool
“This is an antique English fusee pocket watch movement attributed to circa 1830 and signed by John Harrison of Liverpool. The movement features a gilt 3/4 plate construction wit…”
Wristwatch
Greubel Forsey Quadruple Tourbillon in platinum, No. 35
“Source reports describe this Greubel Forsey Quadruple Tourbillon wristwatch, numbered 35 and dating to circa 2009, as cased in a four-part platinum case measuring 43.5 mm in dia…”
Clock
Webb C. Ball Hanging Regulator Clock
“Webb C. Ball Hanging Regulator Clock”
Pocket watch
Lepaute 18th-century gold pocket watch
“This 18th-century French pocket watch is housed in an 18-karat gold case measuring 4.5 cm in diameter. The source reports indistinct hallmarks on the case and a white enamel dia…”
Pocket watch
James McCabe 1834 Gold Lepine Calibre Duplex Pocket Watch
“Plain balance cock fitted with a steel regulator index pointing to a scale engraved 'Slow' and 'Fast', with an endstone setting.”
Pocket watch
Elgin B. W. Raymond Railroad Pocket Watch Model 15 Grade 472
“This open-faced Elgin B. W. Raymond railroad-grade pocket watch is dated by the seller to 1927 and is powered by a 16-size manual-winding Model 15, Grade 472 movement. The 21-je…”