Definition of "unclosed"

...and in one of the window-seats was a volume of Sir Philip Sydney's "Arcadia:" a few myrtle leaves were scattered on the yet unclosed page, a graceful mark to find the place where the youthful reader had brooded over visions of truth and love, already vanished, like the freshness of those leaves, strewed, as if they were flung on the shroud of departed hope.

1837, L[etitia] E[lizabeth] L[andon], “Chapter XXXIV. Confidence.”, in Ethel Churchill: Or, The Two Brides. […], volume I, London: Henry Colburn, […], page 299

By 1875 the Metropolitan and the District were carrying about 100 million passengers a year on their branches and their unclosed circle.

2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, page 64