In this little pleasant Valley, the Springs serve not only to water the Grounds, but for the driving of 18 Powder Mills, 5 whereof were blown up in a little more than halfe a Years Time. 'Tis a little Commonwealth of Powdermakers, who are as black as Africans. Here is a Nursery of Earth for the making of Salt-Petre: There is also here a Boyling-House, where the Salt-Petre is made, and shoots; a Corneing House, and separating and finishing Houses, all very well worth the seeing of the Ingenious. I had almost forgot the Brimstone Mill, and the Engine to search it.  (Quote from John Aubrey, late 17th century)