Long Keeping longkeeping.com · Reading room
Patent · 1888 · age 32

US Patent 390415

by Nikola Tesla

Kept from patents.google.com · 1 file · 49 KBCall number TES PT1888.13

Provenance

Source
patents.google.com
Retrieved
1 October 2026
Source terms (summary)
Google terms: automated access against robots.txt counts as abuse
Rights
Public domainPatent text by Tesla, who died in 1943.Basis: author death year 1943, under a life-plus-70-years rule, as of 2026; other rules, such as the United States publication-date rules, are not assessed.
Formats
HTML
Fingerprint
71961758914fb4c9c81481867c8ff318d3a4257ef696ff71581464f572b41cfesha256 of the file (64 characters). Any change to the file changes this code.
Cite as
Nikola Tesla, US Patent 390415 (1888). Long Keeping, call number TES PT1888.13. https://longkeeping.com/nikola-tesla/us-patent-390415/
Unchanged since collected At the last check, on 2 October 2026, all 903 originals, this work's file among them, matched the fingerprints recorded when they were collected. Each copy is re-checked by hand once a year; there is no automatic alert yet.

Notes on this copy

  • #2Machine-read text (OCR), not proofread, with no page images in the file to check it against.

Original

googlepatents_US390415A.html

Open reading copy 49 KBExact filePublic domain

Reading copy: the saved page with its pictures left out. A picture appears in the reading copy only once the library has recorded its licence, the licence is on the library's pass list, and it has been checked for a likeness. See its pictures at the source (another site). Exact file: the page byte for byte; its pictures do not load here.

Files

First pass, not a clearance.

Links inside these saved pages were written for the site they were saved from; some lead nowhere here.

FileFormatSizeSourcesha256Label
googlepatents_US390415A.html exact filemain HTML 49 KB patents.google.com 71961758914fb4c9c81481867c8ff318d3a4257ef696ff71581464f572b41cfe Public domainPatent text by Tesla, who died in 1943.Basis: author death year 1943, under a life-plus-70-years rule, as of 2026; other rules, such as the United States publication-date rules, are not assessed.