Component · Balance and hairspring assembly

Elgin No. 239 Veritas Hairspring and Balance Assembly

Partially verified

This horological component comprises the hairspring and balance assembly identified by the source as originating from an Elgin No. 239 Veritas pocket watch movement. The source reports the parent movement as an 18-size, Model 8, 21-jewel mechanism bearing serial number 9348026 and dating to circa 1902. As visible in the photograph, the assembly incorporates a split bimetallic balance wheel fitted with threaded perimeter timing screws. Centered around the balance staff pivot is a blued steel hairspring formed with a raised Breguet overcoil terminal curve, pinned to a brass collet at the center and terminating at a hairspring stud.

Oblique macro view of the balance wheel and blued Breguet hairspring assembly from Elgin movement serial 9348026 — Nathan Moore / Pocket Watch Database Blog. Rights pending — permission not yet requested. Original source

Catalogue identity

Source: blog.pocketwatchdatabase.com
Category: Component · Balance and hairspring assembly
Maker / attribution: Elgin National Watch Company
Reference: No. 239 Veritas / Model 8
Catalogue / lot identifier: Source URL identifies the listing
Source-reported date: c. 1902
Country: United States
Source-reported serial: 9348026

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Reported Movement Identity and Provenance

The component is documented by the source as a hairspring and balance originating from an Elgin No. 239 Veritas movement. The parent mechanism is reported as an 18-size, Model 8 grade equipped with 21 jewels.

The source dates the host movement to circa 1902 and records the serial number 9348026. Because only the detached balance assembly is displayed without movement plates or movement markings, these specifications represent source-reported documentation rather than direct observations.

Evidence for this section

“Pictured: Hairspring and Balance from Elgin No. 239 Veritas – 18-Size, Model 8, 21 Jewels, c.1902, Serial No. 9348026”

Observed Construction and Regulating Elements

Visual observation of the detached component shows a bimetallic compensation balance wheel characterized by cuts through the rim and threaded timing screws mounted along its outer perimeter.

The regulating assembly includes a blued steel spiral hairspring with a raised Breguet overcoil terminal curve. At the center, the inner coil is pinned to a slotted brass collet around the balance staff pivot, while the outer coil terminates at a triangular hairspring stud.

Evidence for this section

“Blued steel spiral hairspring with a clearly raised Breguet overcoil terminal curve.”
“Bimetallic compensation balance wheel with cuts through the rim and threaded timing screws along the perimeter.”
“Central steel balance staff pivot protruding through a slotted brass collet securing the innermost hairspring coil.”
“Outer coil terminated at a triangular hairspring stud.”

Historical Documentation Context and Limitations

The source reproduces an excerpt from Elgin's 1901 promotional booklet, 'The Watch Word is Elgin: Timemakers and Timekeepers,' asserting that all hairsprings in the Veritas model featured a Breguet overcoil to prevent accidental quickening of the balance. The booklet text claims that each hairspring was individually formed and overcoiled after tempering and hardening rather than through a mechanical shaping process.

The record is limited strictly to the solitary balance and hairspring assembly resting on a textured surface. Surrounding components—including the balance cock, jewel settings, escapement, and host movement plates—are neither pictured nor verifiable from this artifact alone.

Evidence for this section

“All hairsprings used in the “Veritas” model – as well as in all other Elgin movements – have the Breguet overcoil, which prevents accidental quickening of the balance.”
“The overcoiling of the spring, after tempering and hardening, permits a scrupulous examination that is precluded by the time-saving expedient of tempering and hardening in form by mechanical process.”
“Balance assembly resting unmounted on a textured brown surface.”

Open research questions

Are the original balance cock and movement plates for serial number 9348026 preserved elsewhere?
Does microscopic inspection reveal whether the balance staff or hairspring collet were replaced during subsequent servicing?
What specific timing screw alloy compositions were utilized on Elgin Model 8 balance wheels of this production run?

Source evidence

Recorded claims and source quotations for Elgin No. 239 Veritas Hairspring and Balance Assembly
Field	Source-reported value	Source quotation
Source Identification	Hairspring and Balance from Elgin No. 239 Veritas – 18-Size, Model 8, 21 Jewels, c.1902, Serial No. 9348026	“Pictured: Hairspring and Balance from Elgin No. 239 Veritas – 18-Size, Model 8, 21 Jewels, c.1902, Serial No. 9348026”
Hairspring Feature	Breguet overcoil	“All hairsprings used in the “Veritas” model – as well as in all other Elgin movements – have the Breguet overcoil, which prevents accidental quickening of the balance.”
Source Booklet Publication	The Watch Word is Elgin: Timemakers and Timekeepers (1901)	“The Watch Word is Elgin: Timemakers and Timekeepers, 1901”
Reported Forming Process	Formed individually by an expert workman and overcoiled after tempering and hardening	“Each Elgin hairspring is formed by an expert workman for the individual movement in hand at the time, assuring an absolute fitting to the temperament of the watch it is to serve. The overcoiling of the spring, after tempering and hardening, permits a scrupulous examination that is precluded by the time-saving expedient of tempering and hardening in form by mechanical process.”

Visible details

Blued steel spiral hairspring with a clearly raised Breguet overcoil terminal curve.
Bimetallic compensation balance wheel with cuts through the rim and threaded timing screws along the perimeter.
Central steel balance staff pivot protruding through a slotted brass collet securing the innermost hairspring coil.
Outer coil terminated at a triangular hairspring stud.
Balance assembly resting unmounted on a textured brown surface.

Research qualifications

Only the detached balance and hairspring assembly is shown; the movement plates and remaining mechanism of serial 9348026 are not pictured.
Movement grade, jewel count, and serial number are based on source documentation and cannot be independently confirmed from the balance assembly alone.

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Breguet Hairspring and Balance from Elgin No. 239 Veritas - Pocket Watch Database Blog

Reviewed 2026-10-21 · Record bdb5b13c84

Terms in this record

Glossary explanations for terms named in this object’s record.