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 “Lawler's Patent Model of a Hot Water Heater - 1877” — 40 records examined, 19 dropped by the rights gate.
Archives queried 2026-09-05 17:15 UTC · fetched live for this request
isPublicDomain field is true for this object.metadata_usage.access reads CC0 — a waiver, not an expired term.
Lawler's Patent Model of a Hot Water Heater - 1877
Artist not stated in the record · 1877-04-10
Ericsson Hot-Air Engine, Patent Model
Artist not stated in the record · 1860
Sturtevant’s Patent Model of a Heating and Ventilating Apparatus – ca 1870
Artist not stated in the record · ca 1870
Stevens Steam-Engine Condenser, Patent Model
Artist not stated in the record · 1863
Vera’s Patent Model of a Friction Heater – ca 1869
Artist not stated in the record · 1869-01-19
McAvoy’s Patent Model of a Heat Regulator for Hot Water Apparatus - ca 1869
Artist not stated in the record · 1869-07-27
Ericsson Hot-Air Engine, Patent Model
Artist not stated in the record · 1880-03-30
Colwell Disulphide of Carbon Generator and Engine, Patent Model
Artist not stated in the record · 1879
Ericsson Air Engine, Patent Model
Artist not stated in the record · 1858
Adam’s Patent Model of a Stove Drum - ca 1868
Artist not stated in the record · 1868-12-22
Mauzey’s Patent Model of a Solar Heater – 1880
Artist not stated in the record · 1880
Webster’s Patent Model of a Hot-Air Furnace - ca 1866
Artist not stated in the record · ca 1866
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. 3876502 matched · 40 examined · 19 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 17:15 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.