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 “Allen Cut-Off Valve Gear, Patent Model” — 38 records examined, 23 dropped by the rights gate.
Archives queried 2026-08-29 13:54 UTC · fetched live for this request
isPublicDomain field is true for this object.metadata_usage.access reads CC0 — a waiver, not an expired term.
Allen Cut-Off Valve Gear, Patent Model
Allen, Horatio · 1848
Allen Cut-Off Valve Gear, Patent Model
Artist not stated in the record · ca 1857
Allen Cut-Off Valve, Patent Model
Artist not stated in the record · 1842
Sickels Drop Cut-Off Valve Gear, Patent Model
Artist not stated in the record · 1842
Babcock and Wilcox Valve Gear, Patent Model
Artist not stated in the record · 1866
Thompson Balanced and Cut-Off Valve, Patent Model
Artist not stated in the record · 1875
Uhry and Luttgens Valve Gearing, Patent Model
Artist not stated in the record · 1855
Allen Two-Motion Cone-Valve, Patent Model
Artist not stated in the record · 1855
Sickels Tripping Cut-Off Valve, Patent Model
Artist not stated in the record · 1852
Bartlett Poppet Valve Gear, Patent Model
Artist not stated in the record · 1867
Loper Marine Steam Engine, Patent Model
Artist not stated in the record · 1849
Corliss Steam-Engine Governor, Patent Model
Artist not stated in the record · 1882
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. 38 matched · 38 examined · 23 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 2026-08-29 13:54 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.