John Constable · Yale Center for British Art · B1981.25.147
Cloud Study
“25th Septr. 1821 about from | 2 to 3 afternoon looking to | the north- | Strong Wind at west, bright | light coming through the | Clouds which were laying | one on another”
Museum transcription. Source record. Each underlined phrase links to its claim.
The museum transcription gives 25 September 1821 and approximately 2–3 in the afternoon. The solar calculation uses the midpoint, 14:30 local mean time, as an assumption.
Finding · Nephos analysis · version 2026-09-09
Constable and Howard both give W. That partly agrees with the written wind, while its strength remains untested. Howard’s “Overcast” cannot determine the momentary light through layered clouds described by Constable.
The Nephos method
How this study was read
The method in fullWhat is written
25 September 1821, about from 2 to 3 afternoon.
25th Septr. 1821 about from 2 to 3 afternoon looking to the north- Strong Wind at west, bright light coming through the Clouds which were laying one on another
Yale Center for British Art, B1981.25.147, as the museum transcribes it
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.
Each claim tested
- “25th Septr. 1821” The museum transcription gives 25 September 1821 and approximately 2–3 in the afternoon.
- “about from | 2 to 3 afternoon” The computed Sun describes the light available at an assumed place and hour.
- “looking to | the north-” No independently identified landmark or measured painted solar direction fixes the painting’s bearing.
- “Strong Wind at west,” Both give W.
- “bright | light coming through the | Clouds” Howard describes the day as “Overcast.” His note does not determine whether light broke through a particular part of the sky during the stated hour.
- “which were laying | one on another” No independent cloud-layer observation at Constable’s position is supplied by the register or the regional cloud fraction.
Verdict
Constable and Howard both give W.
- Partially agrees“Strong Wind at west,”
- Unknown“25th Septr. 1821”, “about from | 2 to 3 afternoon”, “looking to | the north-”, “bright | light coming through the | Clouds”, “which were laying | one on another”
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.
| Claim | Howard registerPrinted table · Source | Weather reconstruction20th Century Reanalysis · Source | The sunComputed · Hampstead assumed · Source | Verdict and limit |
|---|---|---|---|---|
| “25th Septr. 1821” Unknown |
The register has an entry for this day. Nothing in it names a painter. Page image | — | — | The museum transcription gives 25 September 1821 and approximately 2–3 in the afternoon. The solar calculation uses the midpoint, 14:30 local mean time, as an assumption. No independent source assembled here dates the painting. Link to claim |
| “about from | 2 to 3 afternoon” Unknown |
— | — | 27.8° altitude · 226.2° azimuthAt 14:30 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 |
| “looking to | the north-” Unknown |
— | — | 27.8° altitude · 226.2° azimuthAt 14:30 local mean time; Hampstead assumed. Computation. | No independently identified landmark or measured painted solar direction fixes the painting’s bearing. The solar position alone cannot establish the stated view. Link to claim |
| “Strong Wind at west,” Partially agrees |
WPage image | Wind from 220° · 3.5 m/s; 85 ± 23% cloud; 16.0 ± 3.0°C15:00 UTC; a regional cell, about 111 × 68 km. Mean and one-sigma spread. Query sources. | — | Both give W. Howard’s daily direction is from another place and contains no measure of “Strong”; the whole wind claim is only partly supported. Link to claim |
| “bright | light coming through the | Clouds” Unknown |
“Overcast.” Note page image. | — | — | Howard describes the day as “Overcast.” His note does not determine whether light broke through a particular part of the sky during the stated hour. Link to claim |
| “which were laying | one on another” Unknown |
“Overcast.” Note page image. | Wind from 220° · 3.5 m/s; 85 ± 23% cloud; 16.0 ± 3.0°C15:00 UTC; a regional cell, about 111 × 68 km. Mean and one-sigma spread. Query sources. | — | No independent cloud-layer observation at Constable’s position is supplied by the register or the regional cloud fraction. 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 · 25 September 1821
The printed register
W · 66° / 54°F
Wind and first thermometer, maximum/minimum for 25 September 1821. Page image.
“Overcast.” 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
27.8° altitude · 226.2° azimuth
At 14:30 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 220° · 3.5 m/s; 85 ± 23% cloud; 16.0 ± 3.0°C
15:00 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
- The museum transcription gives 25 September 1821 and approximately 2–3 in the afternoon. The solar calculation uses the midpoint, 14:30 local mean time, as an assumption. 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.
- 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 B1981.25.147. 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.
The museum’s catalogue remains the authority. Nephos does not claim endorsement.
06 · Sources
Follow every claim.
- M1Yale Center for British Art: John Constable, Cloud Study, B1981.25.147. Object page; museum transcription. The catalogue date gives the year and the museum transcription supplies the full day.
- 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.
- 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.
- R1NOAA-CIRES-DOE 20th Century Reanalysis v3. tcdc mean · tcdc spread · uwnd mean · uwnd spread · vwnd mean · vwnd spread · air mean · air spread