{
 "schema": "nephos.method.v1",
 "slug": "church-niagara-1857",
 "title": "Frederic Edwin Church, Niagara (1857)",
 "urls": [
  "/studies/church-niagara-1857"
 ],
 "written": {
  "summary": "The NGA catalogue dates field visits to four months of 1856 and describes a Canadian-side composition assembled from several viewpoints in the studio. The canvas is dated 1857; no painted weather day is established.",
  "items": [
   {
    "quote": "His first trip was in March 1856",
    "source": "Franklin Kelly, Corcoran catalogue (2011), p. 112",
    "url": "https://drupal-prod.nga.gov/sites/default/files/migrate_images/content/dam/ngaweb/research/publications/pdfs/corcoran-american-art.pdf#page=116"
   },
   {
    "quote": "He was back in July and then in September and October",
    "source": "Franklin Kelly, Corcoran catalogue (2011), p. 112",
    "url": "https://drupal-prod.nga.gov/sites/default/files/migrate_images/content/dam/ngaweb/research/publications/pdfs/corcoran-american-art.pdf#page=116"
   }
  ]
 },
 "records": [
  {
   "name": "ECCC TORONTO, Climate ID 6158350",
   "detail": "70.9 km from the falls reference. 123 daily entries in the four visit-month envelopes; each month remains separate.",
   "url": "https://climate.weather.gc.ca/climate_data/bulk_data_e.html?format=csv&stationID=5051&Year=1856&Month=3&Day=1&timeframe=2&submit=Download+Data"
  },
  {
   "name": "Computed sun and rainbow cone",
   "detail": "Approximate NOAA solar positions and NWS primary-bow radius. Illustrative solar hours, not weather observations or a fit to the canvas.",
   "url": "https://gml.noaa.gov/grad/solcalc/solareqns.PDF"
  }
 ],
 "gaps": [
  "Fort Niagara is closer (20.5 km), but all its visit-month measurement fields are blank.",
  "Exact visit days and a unique compass-calibrated viewpoint remain unestablished. The original artist letters, a dated sketch inscription and original exhibition-review scans were not verified.",
  "No local weather witness, sunshine series or river discharge record has been established. The Toronto archive’s exact historical instrument and site continuity are not reconstructed."
 ],
 "tests": [
  {
   "claim": "Does the canvas preserve the weather of one field visit?",
   "result": "Unknown. Multiple visits and a composite studio view are documented; the monthly envelopes cannot identify a painted day."
  },
  {
   "claim": "Does the rainbow establish that rain fell?",
   "result": "No. A sunlit spray bow requires droplets and illumination; a rainfall total at Toronto cannot establish either at Niagara."
  },
  {
   "claim": "Can geometry date the rainbow?",
   "result": "No. Computed cone orientations show how solar height changes the bow; the painted viewpoint and angular scale are not calibrated."
  }
 ],
 "finding": "A carefully constructed view can look immediate without preserving a single weather moment. Regional daily records give the documented visit months a setting; local light, spray and flow remain unresolved.",
 "verdicts": [
  {
   "claim": "Regional context for the documented visits",
   "verdict": "Partially agrees",
   "reason": "Daily station data survive for the four named months; dates of presence within them remain unknown."
  },
  {
   "claim": "Weather and rainbow in the finished canvas",
   "verdict": "Unknown",
   "reason": "Neither the regional records nor illustrative geometry establish an observed sky or a dated rainbow."
  }
 ],
 "limits": [
  "Separate whole-month arithmetic means of ECCC daily mean temperatures; separate sums of daily liquid rainfall (mm) and snowfall (cm). No averaging between stations or across visit months.",
  "Blank flag plus a finite numerical value is accepted; T is retained as a trace encoded as zero for precipitation sums. Missing or other flags become null with a reason. A monthly value needs every calendar date and accepted component.",
  "A total with traces is the sum of measurable amounts, with unquantified trace amounts additional; T does not mean no precipitation. Snowfall centimetres are not millimetres of rain or snow depth on the ground.",
  "One-year regional context, no historical rank, modern normal or anomaly. Historical instrument/exposure and observing-day changes are not homogenized. No local sunshine, cloud register, discharge or artist-session link has been established.",
  "No unique Canadian-side viewpoint, compass calibration, angular scale or spray elevation is established for the composite painting. These positions describe possible cone orientations at the falls, not proof that a cone intersects the painted spray. A negative top elevation places the entire bow below the astronomical horizon; spray below eye level can still intercept it. No weather, sunlight occurrence, rainbow sighting or painted hour is inferred."
 ]
}