The publisher's decision to date the
General Index 1820 contributes to the confusion over the QR's real
publication dates and the dates that appear on the journal's title pages
(concerning which, see this website's essay
on the topic). The first part of the General Index was published
in March 1820 and the second part in June of that year. As the year on the
title page for Volume 19 is 1818 and that for Volume 21 is 1819, the sequence
of the
QR's title page dates was therefore corrupted.