Accounts and other records of a Derbyshire lead-mining concern, March 1674 - January 1688 (4v-97r, 216r-221r, 225v-236v), written in Steven Flamsteed's hand, and featuring his signature and that of Cornelius Vermuyden. The book was used subsequently by John Flamsteed for copies, written in various hands, of letters dating from 10 July 1688 onwards, chiefly January 1698 - 25 April 1719. There are notes about negotiations over the publication of Flamsteed's works (passim between 121r and 132r, plus 142r-143r, 148v-150r, 209v-211r); 'An Account of the Observatory', 1708 (162v-163v); 'Notes to my State of the Observatory' (176r-177v); a pupil's bill (178v-179r); and work on refractions (189v-192r). There are 238 folios in total.

The correspondents are Luke Leigh; Thomas Bagshaw, Bakewell; [John] Colson, London; Mr Stileman, Burstow; William Bossley, Bakewell; James Pounds, China; Mrs Symonds, Clapham; Sir Simon Degg, Derby; John Gisborne, Derby; Thomas Perkins, London; the Revd John Smith, Gate Burton, Lincolnshire; Sir John Worden; Captain Jevell, Copenhagen; John Caswell; George Clark, Secretary to Prince George of Denmark; Isaac Newton; Abraham Sharp; James Hodgson; William Whiston; Secretary H. St John; George Young; [Dr] John Arbuthnot; Henry Chart, Burstow; Sir Christopher Wren; Dr [John] Wallis; Mr Sheppey, Burstow; Leibnitz (through the Royal Society); John Lowthorp; Thomas Sherlock; John Richards, Nottingham; Edmund Greenbury, Beverley; the Revd [John] Harris; George Kent, Derbyshire; A[wnsham]; and J[ohn] Churchill.