It is said Il Signor J.B. Piranesi, the architect, who published the antiquities of Rome, and divers ingenious works of that kind, has taken accurate plans of the Attic order, and every other particular relating to it. These he proposes to engrave and publish, with exact explanations annexed to them; together with a plan of the whole, as he believes it appeared in its original splendor and perfection; that posterity may not be deprived of informations, which are of so great benefit and importance to all lovers of architecture. It is also said, that the engineer [carpenter], who invented the scaffolding, has made an exact model of it for him; which he intends to publish as a part of the work before-mentioned. XVII. _An Account of a new medicinal Well, lately discovered near_ Moffat, _in_ Annandale, _in the County of_ Dumfries. _By Mr._ John Walker, _of_ Borgue-House, _near_ Kirkudbright, _in_ Scotland. [Read Feb. 10, & Mar. 3, 1757.] THIS mineral spring was found out by one Mr Williamson, a few years ago, when he was overseeing a mine, which was at that time carrying on in its neighbourhood. It is situate about four miles distant from Moffat, in the bottom of a deep scar, which is on the west side of a large mountain called Hartfell, from which it has acquired the name of Hartfell-spaw. This scar is a part of the mountain, thro’ which a small stream of water has worn its way to a considerable depth; by which it has laid open, and exposed to view, the strata of the earth on each side: and in the bottom of this scar, and near to the brink of this small brook, the mineral water springs up. When I saw it, it consisted of two springs, which were very well ordered by Mr. Williamson, so as to run from two wooden spouts, immediately at their rise out of the earth; which indeed must be of very great advantage to all mineral waters; and I am persuaded there are many, whose medical qualities are greatly impaired by falling into reservoirs, and continuing in them for some time after they spring from the earth. The one of these springs was situate about ten or twelve yards farther up the brook than the other; and they were then distinguished by the names of the upper and lower spring: but I have been since informed, that their situation is now altered. Each of these springs did at that time run nearly the same quantity of water, which, as I thought, was above an English quart in a minute, and that during a season of very dry weather.