Page:Philosophical Transactions - Volume 004.djvu/122

 I can give you no accompt of any thing to the southward of 37. degrees; those few ships, that have adventured to 38, reporting the Winds and Seas so raging, that none dare go further.

Hereas among the Materials for Building, that for Covering is not the least to be considered, among the kinds thereof our Country-slate is not to be despised, and that as well for its Stateliness, as Permanency; to which may be added its Cheapness. The first whereof needs no better Evidence, than the Esteem, the slated Houses in or about London (though there are many of them) generally meet with from all, that but take notice of them. For the Second, we have some sorts, which by the conjectures of the most experienced Helliers (or Coverors with Slat) have continued on houses severall hundreds of years, and are yet as firm, as when first put up. And for the third, the computation of Charges, annexed below, may give some hints, as easily to guess at the whole Charge thereby, as compared with Tiling, Leading, Boarding &c., (comparatis comparandis.)

I shall therefore the less scruple to offer some occasional Trials (though common ones, for ought I know,) whereby the firm and lasting goodness of any Slate may easily be experimented and without expence.

1. Take the thin cleft stone, slat or shindle, and so knock it against any hard matter, as to make in yield a found, If the fsund be good and clear, that sort of stone is not crazy, but firm and good. Or

2. If in hewing it does not break before the edge of the Sects (the hewing instrument of the Slatters) you may not much doubt of the firmness of the Slat. But

3. If after it hath been exactly weighed (and the accompt thereof laid by) it be put, and for 2. 4. or 8. hours left to remaine all under water in a vessel; and afterwards taken up