Nephosthe weather behind the paintings
Cloud Study with Trees by John Constable, B1981.25.152
Yale Center for British Art, Paul Mellon Collection. Public domain. Museum object page.

John Constable · Yale Center for British Art · B1981.25.152

Cloud Study with Trees

27 September 1821 · Oil on paper on board · 6 3/4 × 12 inches (17.1 × 30.5 cm)

“Sept 27th 1821, 10 morning, | fine morning after Rainey | night”

Museum transcription. Source record. Each underlined phrase links to its claim.

Yale transcribes 27 September 1821, 10 in the morning, from a label removed from the verso. This is catalogue evidence for the date, not independent timing of execution.

Finding · Nephos analysis · version 2026-09-09

Howard’s note for the 27th is “Cloudy”; the previous day is “Showery.” Neither specifies the overnight rain or the fine morning in Constable’s note. The weather claim remains unknown.

The Nephos method

How this study was read

The method in full
  1. What is written

    27 September 1821, 10 morning.

    • Sept 27th 1821, 10 morning, fine morning after Rainey nightYale Center for British Art, B1981.25.152, as the museum transcribes it
  2. Records of those days

    • Luke Howard’s registerPrinted daily wind, thermometer and notes, The Climate of London. Kept at Tottenham or Stratford, not Hampstead.
    • 20th Century ReanalysisA modern reconstruction for a 1° cell about 111 by 68 km, estimated from pressure, not observed.
  3. Each claim tested

    • “Sept 27th 1821” Yale transcribes 27 September 1821, 10 in the morning, from a label removed from the verso.
    • “10 morning,” The computed Sun describes the light available at an assumed place and hour.
    • “fine morning after Rainey | night” Howard gives “Cloudy” for the 27th and “Showery” for the 26th.
  4. Verdict

    Howard’s note for the 27th is “Cloudy”; the previous day is “Showery.” Neither specifies the overnight rain or the fine morning in Constable’s note.

    • Unknown“Sept 27th 1821”, “10 morning,”, “fine morning after Rainey | night”

01 · The evidence

The claims and their witnesses.

Each phrase of the inscription is a claim. Each column is a witness that never saw the painting, with its own place, scale and limit.

How to read itRead across one row: the phrase Constable wrote, what each witness can say about it, and the verdict on the right. A dash means that witness has nothing to offer on that claim.

ClaimHoward registerPrinted table · SourceWeather reconstruction20th Century Reanalysis · SourceThe sunComputed · Hampstead assumed · SourceVerdict and limit
“Sept 27th 1821”
Unknown
The register has an entry for this day. Nothing in it names a painter. Page image — — Yale transcribes 27 September 1821, 10 in the morning, from a label removed from the verso. This is catalogue evidence for the date, not independent timing of execution. No independent source assembled here dates the painting.
Link to claim
“10 morning,”
Unknown
— — 31.9° altitude · 146.9° azimuthAt 10:00 local mean time; Hampstead assumed. Computation. The computed Sun describes the light available at an assumed place and hour. No independently identified landmark or measured painted solar direction establishes the time of execution.
Link to claim
“fine morning after Rainey | night”
Unknown
“Cloudy.” Note page image. Wind from 230° · 3.2 m/s; 84 ± 28% cloud; 15.3 ± 2.1°C09:00 UTC; a regional cell, about 111 × 68 km. Mean and one-sigma spread. Query sources. — Howard gives “Cloudy” for the 27th and “Showery” for the 26th. Neither locates rain in the intervening night or establishes a fine morning at Constable’s position.
Link to claim

Described. Words used by a person in a particular context: the inscription and the printed register. A felt quality cannot be converted into a threshold, and strength words have no shared numerical scale.

Modelled. A reconstruction describes a regional cell. It is not an observation at the easel. No weather agreement independently establishes a painting's date.

02 · The witnesses

What each source can reach.

Howard · 27 September 1821

The printed register

NW · 63° / 49°F

Wind and first thermometer, maximum/minimum for 27 September 1821. Page image.

“Cloudy.” Note page image.

The table does not establish conditions at Constable’s position. Supplementary Tottenham observations are kept separate from the main register.

The computed sun

31.9° altitude · 146.9° azimuth

At 10:00 local mean time; 51.560° N, 0.165° W is an assumed Hampstead position. No cited source establishes the clock basis; local mean time there trails UTC by about 40 seconds.

A solar calculation supplies no observation of the painting's execution. No painted angular measurement is established here.

Weather reconstruction

Regional context

Wind from 230° · 3.2 m/s; 84 ± 28% cloud; 15.3 ± 2.1°C

09:00 UTC at 52° N, 0° E. Wind speed and bearing calculated from the mean u/v components; component spreads are retained in the query sources. Cloud and temperature show mean and one-sigma spread. This is a 1° cell about 111 × 68 km. No local wind-strength scale or capture cloud measurement is established here.

03 · Making the artwork

The sky passed through an artist's decisions.

Production uncertainty is separate from weather uncertainty. The located sources do not establish every stage of this object's making, and “unknown” is not evidence that a stage did not happen.

Locationpartly known
No place is transcribed in this museum entry. The exact easel coordinates are not established; the solar comparison uses the assumed Hampstead position.
Date evidence
Yale transcribes 27 September 1821, 10 in the morning, from a label removed from the verso. This is catalogue evidence for the date, not independent timing of execution. Museum source.
Outdoor executionunresolved
The evidence assembled here does not establish that every passage was executed outdoors in the stated interval.
Preparatory work and later changesunknown
No complete sequence or timing of working sessions is established by the sources assembled here. No technical examination of this object is offered.

04 · Revisions

How the reading changed.

9 September 2026First record
Sources assembled
The museum transcription is placed beside the independently dated register and modelled context. Catalogue qualifications remain explicit.
What remains open
This is the first Nephos record for this object. No earlier verdict is being revised.

05 · Take this into your work

A record you can cite, print or embed.

Cite individual claims by their link, and cite museum and historical sources directly when using their statements. Nephos analysis is independent of the holding institution; image licences are separate from the research text.

Machine-readable

For the Yale Center for British Art: this record is for B1981.25.152. If it is right, link it from your object page; if anything is wrong, write to Nephos and it will be corrected the same day.

JSON-LD record

The museum’s catalogue remains the authority. Nephos does not claim endorsement.

06 · Sources

Follow every claim.

  1. M1Yale Center for British Art: John Constable, Cloud Study with Trees, B1981.25.152. Object page; museum transcription. The inscription is on a label removed from the verso, as the museum record states.
  2. H1Luke Howard, The Climate of London, 2nd edition, vol. III (London: Harvey and Darton, 1833); Table CLXXXIV, p. 60; continuation and results, p. 61 Page image. Printed monthly results.
  3. S1Skyfield 1.55 with JPL DE440. Apparent topocentric Sun without atmospheric refraction. The place and clock basis are assumptions; the calculation is recorded in the JSON-LD record.
  4. R1NOAA-CIRES-DOE 20th Century Reanalysis v3. tcdc mean · tcdc spread · uwnd mean · uwnd spread · vwnd mean · vwnd spread · air mean · air spread