The Line of Proportion or Numbers Commonly called Gunter's Line, Made Easie. By the which may be Measured all manner of Superficies and Solids; as Board, Glass, Pavement, Timber, Stone, etc. Also, How to perform the same by a Line of Equal Parts, drawn from the Centre of a Two-Foot Rule. Whereunto is added, The Use of the Line Proportion Improved: all manner of Superficies and Solids may exactly and speedily be Measured without the help of Pen or Compasses, by Inspection, looking onely (sic) upon the Ruler

24mo. 12.5cm, 2nd edition, 3,(1)16,(2), pp.1-50, 71-98, 119-120.(inc. author's advertisement & table), (WANTING pages 51-70 & 99-118 and the folding plate), in full contemporary calf, covers worn, leaves loose, as is (ds1). - A treatise on the slide rule originally published in two parts, in 1667 and 1677, the second edition containing both parts. William Leybourn (1626-c.1770), was a prominent London mathematician and land surveyor. The first part appeared the year after the Great London Fire of 1666 and the author writes in his foreword ". this Treatise may be beneficial and usefull (sic) as well to Gentlemen, and others, who at this time may have more than ordinary occasion to make use thereof, in the Rebuilding of the Renowned City of London, as to Artificers themselves, for whose sakes chiefly it was intended.".