35. What Air-shaft belongs to the Mine? Whether it be _single_, or more than One? Of what breadth the Air-shaft is at the Orifice? Whether it be convenient enough, or not? How neer it is placed to the Groove; and in what position? And if there be _several_ Air-shafts, what their Distances and scituation are in reference to the Groove, and to each other? Or how Air is supplied, if there be no Air-shafts? 36. Whether they meet with any Waters in the Mine? And, if they do, how copious they are; at what depths they occur; how they are qualified; and what way they Spring, &c. 37. Whether they are constant or temporary? whether they increase or diminish notably in Summer or Winter, or at any other time of the year; and if they do, at what season that is; how long it is wont to last; and the proportions of Increase and Decrease? 38. What Expedients and Engines are employed to free the Mines from Water? The materials, the parts, the bigness, the shapes, the coaptation; and, in short, the whole structure, number, and way of applying the Instruments, that are made use off to free the Mines from Water? 39. What are the Conditions, Number, &c. of the _Adits_? 40. Whether the Mine be troubled with _Damps_, and of what kind they are? whether they come often or seldom at any set time, or altogether irregularly? what Signs fore-run them? what mischief they do? what remedies are the most successfully imployed against them, aswell in reference to the Cleering of the Mine, as to the Preservation and Recovery of the Workmen? 41. What Methods the Mine-men use in following the Vein, and tracing their passages under ground (which they call _Plumming_ and _Dyalling_) according to the several exigencies? And whether they employ the Instruments, made with the help of the Load-stone, the same way that is usual; and if not, wherein they differ in the use of the same Instruments; or what Instruments they substitute in their place? 42. What ways they take to secure themselves from the uncertainty, incident to the guidance of _Magnetick_ Needles from the _Iron-Stone_ or Ore, that they may meet with under ground? {336} (of which yet perhaps there is not so great danger, as one may imagine; as far as I could find by a Trial, I purposely made in a Groove, where I was sure, there wanted not Iron-Ore.) And what other wayes may be used to direct Miners without the help of a Load-stone? 43. How the Miners deal with the Rocks and Sparrs, they often meet with, before they come at the Ore? Whether they use Fire to soften, calcine, or crack them? How they employ it, and with what measure of success? 44. What wayes and cautions they use, to free the Mine and secure the Work-men from the inconveniencies and danger accruing from the use of much fire in it? 45. What Instruments they use to break the Rock &c? And how those Instruments are conducive; and how long they last?