The phrase few and far between means: scarce; infrequent; difficult to find or to come by.

This phrase occurs, for example, in ‘Great man’ Leitch back and set to pick up where he left off, an article by Andy Bull about Michael Leitch (born 1988), captain of the Japan national rugby-union team, published in The Guardian (London and Manchester, England) of Saturday 12th November 2022:

England’s fixtures against Japan are so few and far between that English fans might be surprised by how much the game there has moved in the meantime. On the field the pack has grown so much that they outweighed France in one Test in the summer.

There is an isolated early use of the phrase few and far between in a letter, dated 13th July 1668, that the English baronet and politician Ralph Verney (1613-1696) received from his brother, Henry Verney (died 1671), giving him directions about his horses: —as published in Memoirs of the Verney Family from the Restoration to the Revolution 1660 to 1696 (London: Longmans, Green, and Co., 1899), compiled by Margaret M. Verney:

If they will not rest quietly there, rather than suffer them to lead my horses up and down the country (hedges are few and far between) they must be tied againe.

But, apart from that isolated early use, the earliest occurrence of the phrase few and far between that I have found is from The Pleasures of Hope, with other Poems (Edinburgh: Printed for Mundell & Son; and for Longman & Rees, and J. Wright, London, 1799), by the Irish clergyman and author Thomas Campbell (1733-1795): —as reprinted in 1800 by John Furman for Jones Bull, New York:

Cease, every joy, to glimmer on my mind, But leave—oh! leave—the light of hope behind! What though my winged hours of bliss have been, Like angel visits, few and far between.

The following remark is from the review of The Pleasures of Hope, with other Poems, published in The British Critic (London, England) of July 1799:

The line, “Like angel visits, few and far between,” is exquisite.

The English novelist Jane Austen (1775-1817) made Sir Edward comment on Campbell’s line in her unfinished novel, Sanditon: —as edited by Kathryn Sutherland, and published by Oxford University Press in 2021:

But while we are on the subject of Poetry, what think you Miss H. of Burns Lines to his Mary?—Oh! there is Pathos to madden one!—If ever there was a Man who felt, it was Burns.—Montgomery has all the Fire of Poetry, Wordsworth has the true soul of it—Campbell in his pleasures of  Hope has touched the extreme of our Sensations—“Like Angel’s [sic] visits, few & far between.” Can you conceive any thing more subduing, more melting, more fraught with the deep Sublime than that Line?—But Burns—I confess my sense of his Pre-eminence Miss H.

The earliest 19th-century occurrences of few and far between that I have found are as follows, in chronological order—in early use, the phrase chiefly appeared with explicit or implicit reference to Campbell’s line:

1-: From Thaddeus of Warsaw (London: Printed for Longman and Rees, 1804), by the English novelist Jane Porter (1775-1850):

Since the demise of Lady Somerset, this excellent man [i.e., Sir Robert Somerset] drew all his comfort from the amiable qualities of his son Pembroke. Sometimes in his livelier hours, which came ‘like angel visits, few and far between,’ he amused himself with the playfulness of the little Earl of Arun, the pompous erudition of Mr. Loftus (who was become his lordship’s tutor) and giving occasional entertainments to the gentry in his neighbourhood.

2-: From the review of The Peasant’s Fate: a Rural Poem; with Miscellaneous Poems (Philadelphia, 1804), by William Holloway, published in The Monthly Anthology, and Boston Review, containing Sketches and Reports of Philosophy, Religion, History, Arts and Manners (Boston, Massachusetts, USA) of February 1804:

If we must acknowledge, that there are glimmerings of genius sometimes discernible, even candour will allow, that they are, “Like angel visits, few and far between.”

3-: From the review of The Triumph of Music: A Poem, in Six Cantos (1804), by William Hayley, published in The Edinburgh Review, or Critical Journal (Edinburgh, Midlothian, Scotland) of April 1805:

We cannot call that poetry, where the glimmerings of fancy or poetical fire are so ‘few and far between.’

4-: From The American Idler.—No. I, by ‘J.’, published in The Eye (Philadelphia, Pennsylvania, USA) of Thursday 7th January 1808:

The number of men of genius is small, and the number of those who write with effect, still less; they appear “like angel visits, few and far between.”

5-: From The Fire Offices, by ‘J.’, a poem published in The Monthly Mirror: Reflecting Men and Manners. With Strictures on their Epitome, the Stage (London, England) of November 1808:

Now in robe of bombazeen, Sable Night enshrouds the air, Coaches “few and far between,” Rattle thro’ the darken’d square.