On a deeper level in a metaphorical parable Markham fuses the significance of the rockstone "Marle" with his own importance. This is expressed both in the title (s.Faksimile! "Painfully Gathered for the good of this Iland, by a man of great eminence and worth") as well as in the text ("the very true art of the inriching ground by Marle, seemeth to lye hidden in part "): Here he adresses some of his alias Shakespeare's works (Edward II, Henry VI.) These "spectacular" hints are hard to miss and otherwise difficult to interprete .
»(…) as by the innumerable Marle-pits digged and spent so many yeeres past, that trees of 200. or 300.yeeres old, doe now grow vpon them, it may most evidently appeare, besides the which we haue mention of Marle in bookes of gainage or husbandry, that were written in the dayes of King Edward the 2. [Marlowe's Edward the second] or before, howbeit the same manner of tillage, by meanes of the ciuill warres, maintained many yeeres as well in the time of the Barons warres, as of the warres betweene the house of Yorke and the Family of Lancaster,[Shakespeares Henry VI] was so giue queer, and gone out of vse, vntill these 30. or 40. yeeres, that it may be said to haue beene then newly 5 borne and reuiued, rather then restored, because the very true art of inrichin the ground by Marle, seemeth to lye hidden in part …«
Already in "A Way to get Wealth" (1625) Gervase Markham ( click also here!) had reported in detail on the rock "Marle" or "Of Marleing" (page39/40) and closed with a remarkable hint:
"This Marle hath bin made so precious by some writers that it hath beene accounted a fift element, but of this curiosity I will not now dispute."