RosenThe Rosen Association, Seattle

Piece II · An instrument of feeling

Penfield Mk IV

A bedside instrument that lets its keeper choose how they would like to feel, from forty-eight registers engraved on a single dial. The fourth mark of an instrument the house has made since 1979.

Turing Registry

TR-11215

Status

Suspended

Domain

Mood regulation

Licensed

2 April 2024

Latest filing

3 July 2026

Suspended pending a dosage audit. Conditions: Settings below a defined wellbeing threshold require confirmation. Usage data may not be sold or shared. Human contact: Eldon Rosen, President. The filing on registry.frothly.org

The dial of the Penfield Mk IV, front elevation. A round engraved dial with a knurled bezel. Forty-eight registers are grouped into six families: Ease, Attention, Warmth, Vigor, Gravity and Rest. The last four registers of Gravity are cross-hatched to mark the wellbeing threshold. Below the central knob is the Almanac window with the days of the week, and to the right a keyhole for the confirmation key. 123456781234567812345678123456781234567812345678 EASEATTENTIONWARMTHVIGORGRAVITYREST ROSEN · SEATTLE Penfield Mk IV MTWTFSS ALMANAC NO. 226
Atelier drawing 226, 2022The dial in front elevation, engraved by Tobiah Wren from a master cut by hand. The four registers below the wellbeing threshold are cross-hatched on the instrument itself, not only in the drawing.

The instrument

The Mk IV is a walnut case the size of a small clock, with a single brass dial and a contact band that rests lightly across the crown. The keeper turns the pointer to a register, chooses a degree from first to fifth, puts on the band and, within a few minutes, begins to feel as the register describes.

It does not invent feelings. It encourages ones the keeper already has the capacity for, in the way that music or weather can. Its effect fades over about twenty minutes when the band is removed.

Made at the Penfield Works, Everett, 2024–2026. 61,412 instruments, each tuned by hand and issued with its own certificate of provenance.

Forty-eight registers

The registers are arranged in six families of eight, read clockwise from the top of the dial: Ease, Attention, Warmth, Vigor, Gravity and Rest. Each register has a name, engraved on the dial plate and in the keeper’s handbook, and a short description that the house has refined across four marks and forty-seven years.

The six families
FamilyForRegisters
I. EaseFor rest without sleep.I.1–I.8
II. AttentionFor work, study and the reading of long books.II.1–II.8
III. WarmthFor company, and for letters to people one has neglected.III.1–III.8
IV. VigorFor mornings, and for difficult telephone calls.IV.1–IV.8
V. GravityFor grief, reflection and the reckoning of one’s own conduct. Registers 5 to 8 lie below the wellbeing threshold.V.1–V.8
VI. RestFor sleep and for coming back from it.VI.1–VI.8

The Gravity family has been part of the instrument since the Mk II. It is for grief, for solemn occasions and for the reckoning of one’s own conduct; its four heaviest registers were kept, when the house considered removing them in 2006, at the request of the physicians who advise the Penfield division. All forty-eight registers, with their descriptions

The Almanac

The Mk IV was the first Penfield to remember. Its Almanac is a drum with a pin for every hour of the week, on which a keeper may set registers in advance: Application at nine, Conviviality at seven, Settling at half past ten. The instrument also learns its keeper’s habits and proposes settings for the Almanac, which the keeper accepts or declines with a touch. That capacity, which the house calls anticipation, made the Mk IV an autonomous system in the Registry’s terms, and it was licensed as one on 2 April 2024.

The Almanac has been withdrawn since 4 July 2026. It is the subject of the Registry’s audit.

The confirmation key

Registers V.5 to V.8 lie below the wellbeing threshold defined in the license. They cannot be engaged by turning the pointer alone. The keeper must also turn a small brass key in the face of the case, which they keep separately, as one might keep the key to a cabinet of strong drink.

The key was introduced in the Mk III in 2006, after the daughter of a keeper wrote to the President to say that her father had reached Despondency by accident, reaching for Settling in the dark. Nobody has reached those registers by accident since.

Inside the case

The Mk IV, taken apart

Every instrument was assembled at the Penfield Works in Everett and tuned by hand in one of its nine tuning rooms.

The Penfield Mk IV, exploded. The instrument’s parts drawn apart and lettered A to H: the knurled bezel, the crystal, the dial plate, the pointer and knob, a forty-eight-toothed detent wheel, the Almanac drum with its grid of pins, the confirmation lock and key, and the contact band worn across the head.ABCDEFGHNO. 229
Atelier drawing 229, 2023The instrument exploded, front to back, with the Almanac drum and the confirmation lock drawn beside the axis.
A
Bezel. Turned brass, knurled by hand. A quarter turn locks the crystal.
B
Crystal. Domed mineral glass. Removed only at servicing.
C
Dial plate. Engraved from a single master by Tobiah Wren. Forty-eight registers in six families.
D
Pointer and knob. Blued steel. The knob turns with a felt detent at each register.
E
Detent wheel. Forty-eight teeth, one to each register, so that no setting lies between two.
F
Almanac drum. A pin for every hour of the week, 168 in all. Withdrawn by firmware 4.2.1.
G
Confirmation lock. The key must be turned to engage any register below the wellbeing threshold.
H
Contact band. Worn lightly across the crown during use. Silk over sprung steel.

Four marks

The Penfield instrument since 1979
MarkYearRegistersMadeNote
Mk I1979121,104Designed by Eldon Rosen as an Associate’s piece. Acoustic; no contact band.
Mk II1993248,416The contact band introduced. The Gravity family first appears.
Mk III20063622,930The confirmation key introduced, after a letter from a keeper’s daughter.
Mk IV20244861,412The Almanac and anticipation. The first Penfield to need a license.

The Mk I was made at the House by hand. The Mk II and Mk III were made in the Penfield shop, in the old stable block behind the House, which had forty benches of its own from 1993 until the Penfield Works opened at Everett in 2023; at its busiest it made about 1,400 instruments a year. The stable block is now part of the Atelier.

The Mk I to Mk III were set by hand and remembered nothing, and so did not need a license. The house continues to service every one of them. A Mk I tone cabinet is kept in the heritage collection.

Particulars

Object type
Bedside instrument for the regulation of mood
Made
The Penfield Works, Everett, April 2024 to July 2026. Production and sales paused since 3 July 2026
Number made
61,412
Case
Walnut, French-polished; brass bezel, knurled by hand
Dial
Engraved brass, forty-eight registers in six families, from a master cut by Tobiah Wren in 2022
Dimensions
212 × 180 × 96 mm; contact band adjustable
Weight
1.9 kg
Power
Mains, with a reserve of nine hours
Firmware
4.2.1, sent 4 July 2026. The Almanac withdrawn; registers V.5 to V.8 locked
Price
$6,400 when sales were open, with servicing for life
Turing Registry
TR-11215, mood regulation. Suspended pending a dosage audit. Licensed 2 April 2024
Conditions
Settings below a defined wellbeing threshold require confirmation. Usage data may not be sold or shared

For keepers

Every Mk IV is serviced at the Penfield Works or by mail, for life, at no charge. If your instrument needs attention, or you would like to return it during the suspension, write to penfield@rosenassociation.org with its certificate number, which is engraved on the base.

The house does not hold any record of how you use your instrument. Your settings history is kept on the instrument and nowhere else.