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rant. In fine, he must follow the Exam-ple of the nice Court Surveyor, that notonly points out the safest Roads and Har-bours, but likewise manifests the dangerousSands and Rocks ; therefore let the subter-ranean Geographer describe the barren aswell as the fertile Mountain, for by thathe will give us to understand the promisingOre bearing Signs, and ‘vice versa ; for agood Guide ought not only to be acquaint-ed with the main Road through which heis to conduct his Traveller, but he shouldalso know the bye ones, that he may notbe at a Lois to get into. the main one, if byany Accident he should happen to bethrown out of it.

6thy, When he comes to the smeltingPart, he must lay down a general Historyof the Produce of Nature in the Cavernsof the Earth ; he must give us a Descripti-on ot the various Sorts of Ores and Mi-nerals, by shewing us not only the differentProperties which essentially distinguish oneSpecies from another, but likewise the Di-versity that may be found in each Specie ;these, according to their several Degreesand Natures, are to be distributed into pro-per Classes, divided and subdivided underproper Heads ; giving to each its insepa-rable Characteristicks, whereby to distin-guish it from the rest ; telling us how andwhere they are commonly found, what

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