10 PHILOSOPHICAL TRANSACTIONS. [aNNO 1665. 



nor that, over against the perigee of all the other comets of which particular 

 observations are recorded, are always found stars of the first magnitude, or such 

 others as are very notable, besides other reasons that might be alleged, I shall 

 not pursue this speculation ; but rather suggest what I have taken notice of in 

 my reflections upon former comets, which is, that more of them enter into 

 our system by the sign of Libra and about Spica virginis, than by all the other 

 parts of the heavens. For both the present comet, and many others register- 

 ed in history, have entered that way, and consequently passed out of it by the 

 sign Aries ; by which also many have entered. 



I have observed the position of the comet since January 28, every day, when 

 the weather permitted, viz. January ig, Februarys, 6, 10, 17, 19, 24, 26, 

 27, and March 6, 7, 8. I left it on March 8, at the 18° of the horn of Aries, 

 almost in the same latitude ; and I am apt to believe, it will be eclipsed ; which 

 I wish I may be able to observe this evening, if it be not already passed. 



On the Mines of Mercury in Friidi ; and a JVay of producing Wind 

 hy the Fall of Water. By Dr. Walter Pope. N' 2, p. 21. 



The mines of mercury in Friuli, a territory belonging to the Venetians, are 

 about a day's journey and a half distant from Goritia northwards, at a place 

 called Idria, situated in a valley of the Julian Alps. They have been, as I am in- 

 formed, these l6o years in the possession of the emperor, and all the inhabi- 

 tants speak the Sclavonian tongue. In going thither, we travelled several 

 hours in the best wood I ever saw before or since, being very full of firs, oaks, 

 and beeches, of an extraordinary thickness, straightness, and height. The town 

 is built, as usually towns in the Alps are, all of wood, the church only except- 

 ed, and another house wherein the overseer lives. When I was there, in 

 August last, the valley, and the mountains too, out of which the mercury was 

 dug, were of as pleasant a verdure as if it had been in the midst of spring, 

 which they there attribute to the moistness of the mercury ; how truly, I dispute 

 not. That mine which we went into, the best and largest of them all, was 

 dedicated to Saint Barbara, as the other mines are to other saints : the depth 

 of it was 125 paces, every pace of that country being, as they informed us, 

 more than five of our feet. There are two ways down to it ; the shortest per- 

 pendicular way is that whereby they bring up the mineral in great buckets, 

 and by which oftentimes some of the workmen come up and down. The other, 

 which is the usual way, is at the beginning not difficult, the descent not being 

 much ; the greatest trouble is, that in several places you cannot stand upright : 

 but this holds not long, before you come to descend in earnest by perpendicu- 

 lar ladders, where the weight of one's body is found very sensibly. At the end 



