John Constable · Yale Center for British Art · B1981.25.117
Cloud Study, Early Morning, Looking East from Hampstead
“1/2 p 5 AM 19 July | looking East. | The day beautiful at noon plain blue sky.”
Museum transcription. Source record. Each underlined phrase links to its claim.
The inscription supplies 19 July but no year. Yale's catalogue supplies 1821. Neither the register nor the computed Sun independently dates the painting.
Finding · Nephos analysis · version 2026-09-09
Howard calls the 19th fine, with thunder in the evening. The supplementary Tottenham note calls it a very fine and hot day. These descriptions partly agree with Constable's beautiful day, but neither establishes his plain blue sky at noon. The date, hour and eastward view remain unknown to the independent witnesses.
The Nephos method
How this study was read
The method in fullWhat is written
Hampstead, 19 July 1821, 1/2 p 5 AM.
1/2 p 5 AM 19 July looking East. The day beautiful at noon plain blue sky.
Yale Center for British Art, B1981.25.117, 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
- “1/2 p 5 AM” The computed Sun gives the light available at the assumed place and hour.
- “19 July” The inscription supplies 19 July but no year.
- “looking East.” The computed Sun lies east-northeast at the assumed hour.
- “The day beautiful” Howard's main register calls the day fine; the supplementary Tottenham note calls it very fine and hot.
- “at noon plain blue sky.” Howard's description of a fine day gives no cloud amount at Constable's position at noon.
Verdict
Howard calls the 19th fine, with thunder in the evening.
- Partially agrees“The day beautiful”
- Unknown“1/2 p 5 AM”, “19 July”, “looking East.”, “at noon plain blue sky.”
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 |
|---|---|---|---|---|
| “1/2 p 5 AM” Unknown |
The main register gives a day, not an observation at half past five. Page image | — | 11.0° altitude · 70.1° azimuthAt 05:30 local mean time; Hampstead assumed. Computation. | The computed Sun gives the light available at the assumed place and hour. No independently identified landmark or measured painted solar direction establishes the time of execution. Link to claim |
| “19 July” Unknown |
The table has a row for the 19th. Nothing in it names a painter. Page image | — | — | The inscription supplies 19 July but no year. Yale supplies 1821. No independent source assembled here dates the painting. Link to claim |
| “looking East.” Unknown |
— | — | 11.0° altitude · 70.1° azimuthAt 05:30 local mean time; Hampstead assumed. Computation. | The computed Sun lies east-northeast at the assumed hour. No independently identified landmark or measured painted solar direction fixes the painting's bearing. Link to claim |
| “The day beautiful” Partially agrees |
“Fine: some thunder in the evening, and a brilliant meteor.” Note page image.Tott. (Tottenham): “Very fine and hot day: heavy clouds in the W, which afterwards passed off to the northward, where was much brilliant lightning, about 9, p. m.: one clap followed, and lightning in other quarters.” Page image. | Wind from 134° · 1.7 m/s; 66 ± 39% cloud; 13.8 ± 1.7°C06:00 UTC; a regional cell, about 111 × 68 km. Mean and one-sigma spread. Query sources. | — | Howard's main register calls the day fine; the supplementary Tottenham note calls it very fine and hot. That partly agrees with the description of a beautiful day. The stations did not measure Constable's position, and the evening thunder is kept separate from the daytime claim. Link to claim |
| “at noon plain blue sky.” Unknown |
“Fine: some thunder in the evening, and a brilliant meteor.” Note page image.Tott. (Tottenham): “Very fine and hot day: heavy clouds in the W, which afterwards passed off to the northward, where was much brilliant lightning, about 9, p. m.: one clap followed, and lightning in other quarters.” Page image. | Wind from 134° · 1.7 m/s; 66 ± 39% cloud; 13.8 ± 1.7°C06:00 UTC; a regional cell, about 111 × 68 km. Mean and one-sigma spread. Query sources. | — | Howard's description of a fine day gives no cloud amount at Constable's position at noon. A regional reconstruction cannot establish a locally cloudless sky, and no capture measurement is offered here. 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 · 19 July 1821
The printed register
E · 78° / 52°F
Wind and first thermometer, maximum/minimum for 19 July 1821. Page image.
“Fine: some thunder in the evening, and a brilliant meteor.” Note page image.
Tott. (Tottenham): “Very fine and hot day: heavy clouds in the W, which afterwards passed off to the northward, where was much brilliant lightning, about 9, p. m.: one clap followed, and lightning in other quarters.” Page image.
The main register and the supplementary notes headed Tott. are kept separate. Neither establishes conditions at Constable’s position.
The computed sun
11.0° altitude · 70.1° azimuth
At 05:30 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 134° · 1.7 m/s; 66 ± 39% cloud; 13.8 ± 1.7°C
06:00 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
- Hampstead The exact easel coordinates are not established; the solar comparison uses the assumed Hampstead position.
- Date evidence
- The inscription supplies 19 July but no year. Yale's catalogue supplies 1821. Neither the register nor the computed Sun independently dates the painting. 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 B1981.25.117. 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, Early Morning, Looking East from Hampstead, B1981.25.117. Object page; museum transcription. The catalogue date gives the year and the museum transcription supplies the day and month.
- H1Luke Howard, The Climate of London, 2nd edition, vol. III (London: Harvey and Darton, 1833); Table CLXXXII, p. 56; continuation and results, p. 57 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