At the age of six John lost his sight after a smallpox infection; he was given fiddle lessons as a way of making provision for him to earn a living later in life.

He spent some time living at places on the North Sea coast between Newcastle and London, and lodged with his aunt in Whitby.

[7] His fiddle playing gave him social connections and a patron, Colonel Liddell, Member of Parliament for Berwick-on-Tweed.

[4] During the Jacobite rising of 1745 Metcalf's connections got him the job of assistant to the royal recruiting sergeant in the Knaresborough area.

[2] Before army service, Metcalf worked as a carrier using a four-wheeled chaise and a one-horse chair on local trips.

[8] In 1765 Parliament passed an act authorising turnpike trusts to build toll roads in the Knaresborough area.

He worked out a way to build a road across a bog using a series of rafts made from ling (a type of heather) and furze (gorse) tied in bundles as foundations.

[12] He mastered his trade with his own method of calculating costs and materials, which he could never explain to others, and he became known as one of the fathers of the modern road along with Thomas Telford and John MacAdam.

Blind Jack of Knaresborough died aged 92 on 26 April 1810, at his home in Spofforth where he is buried in the churchyard of All Saints' Church.

[16] His headstone, erected in the churchyard of All Saints' Church, Spofforth, at the cost of Lord Dundas, bears this epitaph: "Here lies John Metcalf, one whose infant sight Felt the dark pressure of an endless night; Yet such the fervour of his dauntless mind, His limbs full strung, his spirits unconfined, That, long ere yet life’s bolder years began, The sightless efforts mark’d th’ aspiring man; Nor mark’d in vain—high deeds his manhood dared, And commerce, travel, both his ardour shared.