OpenTwo archives, queried live.
Every record below comes from The Met or Smithsonian Open Access and was filtered on that archive’s own rights field before it reached this page. 12 shown for “Sturtevant’s Patent Model of a Hot Air Furnace - ca 1869” — 40 records examined, 18 dropped by the rights gate.
Archives queried 2026-09-05 17:23 UTC · fetched live for this request
isPublicDomain field is true for this object.metadata_usage.access reads CC0 — a waiver, not an expired term.
Sturtevant’s Patent Model of a Hot Air Furnace - ca 1869
Artist not stated in the record · ca 1869
Hillson’s Patent Model of a Hot-Air Furnace - ca 1848
Artist not stated in the record · ca 1848
Webster’s Patent Model of a Hot-Air Furnace - ca 1866
Artist not stated in the record · ca 1866
White’s Patent Model of a Hot-Air Furnace - ca 1872
Artist not stated in the record · ca 1872
Fickardt’s Patent Model of a Furnace – ca 1836
Artist not stated in the record · 1836-09-08
Sturtevant’s Patent Model of a Heating and Ventilating Apparatus – ca 1870
Artist not stated in the record · ca 1870
Crocker’s Patent Model of a Hot-Air Furnace - 1874
Artist not stated in the record · 1874
Crane Hot-Air Engine, Patent Model
Artist not stated in the record · 1865
Fowler’s Patent Model of a Furnace Steam Boiler - ca 1856
Artist not stated in the record · ca 1856
Ericsson Air Engine, Patent Model
Artist not stated in the record · 1858
McAvoy’s Patent Model of a Heat Regulator for Hot Water Apparatus - ca 1869
Artist not stated in the record · 1869-07-27
Rider Hot-Air Engine, Patent Model
Artist not stated in the record · 1871
Where these records came from.
Two archives are wired, and only two. Each one is filtered on its own rights field — never on a title match, and never on the presence of an image file.
- The Met Collection API (Open Access)Rights field:
isPublicDomain. The archive returned no records for this term.0 matched - Smithsonian Open Access API (api.si.edu)Rights field:
content.descriptiveNonRepeating.metadata_usage.access. 3895716 matched · 40 examined · 18 dropped by the rights gate. Kept only where metadata_usage.access === "CC0" and an image resource was published.12 shown
These figures describe the pass run at 2026-09-05 17:23 UTC, during this request. A completed pass is kept for 24 hours and replayed for an identical search, which is what keeps repeated queries inside Smithsonian’s 30-requests-per-hour allowance. A pass in which either archive failed to answer is never kept — an outage must not be replayed as though it were a finding about the catalogue.
Wikimedia Commons and the Library of Congress are deliberately not wired. Wikimedia was confirmed, on a live query, to return CC-BY material inside the same result set as genuine public domain works, and filtering it safely has not been designed yet. loc.gov was blocked by bot detection during the source evaluation, so its rights vocabulary has never been observed — and nothing here is built on a field nobody has read.
An image file is a rights claim. It never travels without its field.