There are some Harper's Weekly volumes in archive.org, but I reckon we'd need volume 36 (1892), and the latest I found is volume 14 (1870).
Hathi Trust has some content, but nothing from 1892.
It may be found in the
Library of Congress or in
Indiana University
Or someone could buy it (
http://www.abebooks.com/HARPERS-WEEK...e/753342040/bd,
http://antiques.gift/harpers-weekly-...-_3904520.html)
There's a PDF
here with what could be the cover page of the magazine, but the text is probably the same source as elsewhere.