Courtauld · P.1952.RW.69 Image at museum

The image licence is non-commercial and this record’s permission has not yet been confirmed with the museum.

Image courtesy the Courtauld. IIIF manifest and credit source, C2. Museum copyright policy, C8.

01 / Artwork

John Constable · 1776–1837

Cloud Study

Partial evidence · object secure · regional records only

The museum object and inscription are secure; the atmospheric tests remain limited.

Date: 21 September 1822 C1
Museum: Courtauld Gallery, London (Samuel Courtauld Trust) C1
Accession: P.1952.RW.69 C1
Medium: Oil on two superimposed sheets of wove paper laid down on a third sheet C1
Dimensions: 30.5 × 49 cm C1
Collection page: View the object at the Courtauld C1

Artist’s note

“Sepr.21.1822. Looking South, brisk wind to east, warm and fresh. 3 o’cl. afternoon”

Courtauld catalogue transcription of the inscription on the verso. C1

02 / Atmosphere

Later that
same afternoon.

The Yale analysis supplies a verified regional weather receipt for 21 September. Here it is read at the Courtauld inscription’s later hour without claiming an image measurement.

C6 · Same-day object

Two notes, one moving sky

Yale’s catalogue gives the following text, printed on a label affixed to the stretcher: “Sep[br] 21. 1822. | ½ p’s[t] one o clock. | looking south. | wind very fresh at East, but warm.” This Courtauld sheet says three o’clock, looking south, with a brisk east wind, “warm and fresh.” C1 C6

The notes agree on date, view, easterly wind and warmth. That is internal consistency between two inscriptions from the same hand, not proof from another observer or a claim that the cloud forms should look alike about ninety minutes apart.

No capture-to-capture cloud measurement has been performed. The paintings are compared through verified metadata and inscriptions only.

13:30Yale inscription time

15:00Courtauld inscription time

E / Eboth inscribed easterly

C7 · Solar geometry

The sun at three

At approximately 15:00 local mean time over Hampstead, the sun stood 25.9° high at azimuth 234.1°, in the southwest. For a painter looking south it was to the right, lower than during Yale’s earlier session. C7

Hampstead is the site basis stated for Constable’s cloud-study campaign by the Courtauld. With no horizon, this establishes geometry but cannot test a painted bearing.

Hampstead, 51.56° N, 0.165° W. JPL Horizons / DE441; 15:01 UT approximates 15:00 local mean time.

C4 · Regional reconstruction

The model at 15:00

The same painting-blind 20th Century Reanalysis used for Yale gives a 54° wind from ENE at 6.0 m/s, about 63% cloud cover with ±34 points of ensemble spread, and 13.9°C at 15:00 over the London-area grid cell. C4

At London’s latitude, the regional cell is about 111 × 68 km. It can provide context for direction, broad strength, temperature and cloud amount; it cannot reproduce one Hampstead hilltop.

54°wind from ENE

6.0 m/sgrid-cell wind speed

13.9°Cgrid-cell air temperature

C3 · Period register

Howard’s day reading

Luke Howard’s London-area register records NE for 21 September and calls the 17th through the 21st “Fine.” The Central England daily mean was 11.6°C, slightly below the prior 50-year average for that calendar date, about 12.6°C. The day sat inside a mild spell that fell to 9.5°C by the 26th. C3 C5

Howard’s northeast and the model’s east-northeast sit beside both painters’ east, but adjacent compass sectors are not identical readings.

Howard’s table is a day-level London-area comparison from another location. The temperature series is a regional daily composite; neither it nor the reanalysis defines “warm” or measures Constable’s position.

NEHoward’s 21 September wind

“Fine.”Howard’s note, 17–21

11.6°CCentral England daily mean

03 / Evidence

The verdict,
item by item.

“Sepr.21.1822.”

Unknown

A second inscription by Constable gives the same date. This is internal consistency between two notes from the same hand, not confirmation from a separate observer. C1 C6

“3 o’cl. afternoon”

Unknown

The computed Sun at 15:00 is consistent with the afternoon, but a horizonless pure sky supplies nothing against which to test the stated time. C7

“Looking South,”

Unknown

The computed sun would lie to the right of a south-facing painter, but no painted bearing can be measured from this view. C7

“brisk wind to east,”

Partially agrees

Yale also says East; Howard records NE; the regional model reconstructs ENE at about 6.0 m/s. The easterly sector is consistent across all three, but locations and direction labels differ. C3 C4 C6

“warm and fresh.”

Unknown

The day sat inside a mild spell that fell sharply by the 26th, yet its 11.6°C daily mean was slightly below the prior 50-year average for 21 September, about 12.6°C. No source defines “warm” or “fresh,” and none measures Constable’s position. C4 C5

Same-day consistency

Partially agrees

The two inscriptions from the same hand agree on date, southward view, east wind and warmth. The regional wind records are compatible with the easterly claim; the warmth claim remains unknown. No visual cloud comparison is claimed. C1 C3 C4 C5 C6

What we know / what we cannot know: the object identity and inscription are secure, and the regional records support a broadly easterly afternoon. They do not prove an exact painted bearing, gust strength, temperature adjective or hour from cloud forms alone.

04 / Bottom line

What a visitor can take away.

Constable’s two notes, about ninety minutes apart, agree on the date, southward view, easterly wind and warmth. Because both notes are his, the match is internal consistency, not confirmation from another observer. Regional wind records fit an easterly day, but the picture cannot test the hour or view, and the temperature sources cannot decide what “warm” meant at his position.

05 / Sources

Cloud Study

Artist’s note

Later thatsame afternoon.

Two notes, one moving sky

The sun at three

The model at 15:00

Howard’s day reading

The verdict,item by item.

“Sepr.21.1822.”

“3 o’cl. afternoon”

“Looking South,”

“brisk wind to east,”

“warm and fresh.”

Same-day consistency

What a visitor can take away.

Follow every claim.

Later that
same afternoon.

The verdict,
item by item.