Movement · Demonstration escapement model

Model of Duplex escapement used in Waterbury watches

Partially verified

This object is a demonstration model of a duplex escapement as employed in early Waterbury watches, dated by the Science Museum Group to between 1880 and 1935. Catalogued under accession number 1938-554 Pt1, the mock-up mechanism is constructed from brass and steel. The top plate is engraved with the signature 'Waterbury Watch Co. / WATERBURY, CONN, / U.S.A.' alongside 'DUPLEX'. An exposed balance wheel, blued hairspring, and engraved cock are mounted above the plate, with the movement supported by brass pillars on turned feet.

Three-quarter view of the duplex escapement model mechanism showing balance wheel, engraved cock, and top plate — The Board of Trustees of the Science Museum. Rights pending — permission not yet requested. Original source

Catalogue identity

Source: collection.sciencemuseumgroup.org.uk
Category: Movement · Demonstration escapement model
Maker / attribution: Waterbury Watch Co.
Reference: Not recorded
Catalogue / lot identifier: 1938-554 Pt1
Source-reported date: 1880-1935
Country: United States

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

Object Identity and Origin

This object is catalogued by the Science Museum Group as part 1938-554 Pt1, described as a "Model of Duplex escapement as employed in the early Waterbury watches, 1880-1935". The parent entry 1938-554 credits the acquisition to Mr. Malcolm Gardner.

Visual observation of the top plate records engraved markings reading: 'Waterbury Watch Co. / WATERBURY, CONN, / U.S.A.' and 'DUPLEX'.

Evidence for this section

“Model of Duplex escapement as employed in the early Waterbury watches, 1880-1935”
“credit: Mr. Malcolm Gardner”
“Engraved on the top plate: 'Waterbury Watch Co. / WATERBURY, CONN, / U.S.A.' and 'DUPLEX'.”

Physical Construction and Mechanism

The movement model is listed with measurements "overall: 80 mm 133 mm, 1.325kg" and materials consisting of "steel (metal) and brass (copper, zinc alloy)". Visual observations describe circular brass plates separated by turned cylindrical pillars.

Above the plate, visible features include a prominent brass balance wheel, flat spiral hairspring, and decorative foliate engraving on the cock. A small detached trapezoidal metal piece is also visible to the lower left.

Evidence for this section

“Measurements: overall: 80 mm 133 mm, 1.325kg”
“Materials: steel (metal) and brass (copper, zinc alloy)”
“Circular brass plates separated by turned cylindrical pillars.”
“Fitted with a prominent brass balance wheel, flat spiral hairspring, and decorative foliate engraving on the cock.”
“A small detached trapezoidal metal piece is visible to the lower left.”

Associated Mounts and Documentation Scope

Under parent catalog record 1938-554 ("Model of Duplex escapement, with mahogany base and glass dome"), the piece is categorized under Time Measurement with types noted as "spring-driven watch mechanism , duplex escapement and model". For part 1938-554 Pt1 specifically, the type is designated as "mock-up and escapement".

The museum record also enumerates associated components: part 1938-554 Pt2, catalogued as "Mahogany base and glass dome for model of Duplex escapement as employed in the early Waterbury watches", and part 1938-554 Pt3, catalogued as "Spring only, as employed in the early Waterbury watches, 1880-1935".

Evidence for this section

“type: spring-driven watch mechanism , duplex escapement and model”
“type: mock-up and escapement”
“Mahogany base and glass dome for model of Duplex escapement as employed in the early Waterbury watches”
“Spring only, as employed in the early Waterbury watches, 1880-1935”

Open research questions

What specific role did the small detached trapezoidal metal piece serve within the duplex mechanism?
Was this demonstration model fabricated directly by the Waterbury Watch Co. or commissioned by a third party or collector?
How was part 1938-554 Pt3 (the separate spring) originally installed or demonstrated in relation to Pt1 and the Pt2 mount?

Source evidence

Recorded claims and source quotations for Model of Duplex escapement used in Waterbury watches
Field	Source-reported value	Source quotation
Object Number	1938-554 Pt1	“Object Number: 1938-554 Pt1”
Date	1880-1935	“1880-1935”
Materials	steel (metal) and brass (copper, zinc alloy)	“Materials: steel (metal) and brass (copper, zinc alloy)”
Measurements	overall: 80 mm 133 mm, 1.325kg	“Measurements: overall: 80 mm 133 mm, 1.325kg”
Credit	Mr. Malcolm Gardner	“credit: Mr. Malcolm Gardner”
Parent Record Title	Model of Duplex escapement, with mahogany base and glass dome	“Model of Duplex escapement, with mahogany base and glass dome Model of Duplex escapement as employed in the early Waterbury watches, mounted in mahogany base with glass dome”
Parent Object Number	1938-554	“Object Number: 1938-554”
Part Pt2 Details	overall: 175 mm x 230 mm; mahogany (wood) and glass	“Measurements: overall: 175 mm x 230 mm Materials: mahogany (wood) and glass Object Number: 1938-554 Pt2”
Part Pt3 Details	Spring only; metal (unknown)	“Materials: metal (unknown) Object Number: 1938-554 Pt3”

Visible details

Engraved on the top plate: 'Waterbury Watch Co. / WATERBURY, CONN, / U.S.A.' and 'DUPLEX'.
Fitted with a prominent brass balance wheel, flat spiral hairspring, and decorative foliate engraving on the cock.
Circular brass plates separated by turned cylindrical pillars.
A small detached trapezoidal metal piece is visible to the lower left.

Research qualifications

The mahogany base and glass dome catalogued under part 1938-554 Pt2 are not shown in this photograph.
The exact function of the small detached metal piece visible beside the mechanism is unspecified in the source text.

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

Consulted source

Model of Duplex escapement, with mahogany base and glass dome | Science Museum Group Collection

Reviewed 2026-10-21 · Record 65d917a544

Terms in this record

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