VOL. XIX.] PHILOSOPHICAL TRANSACTIONS. 175 



many parts evidently. Snowdon was measured by Mr. Caswel, with Adams's 

 instruments, and found to be l^JO yards high ; which abating the height of the 

 mercury 3 inches, 8 tenths, may serve for a standard, until a better be obtained 

 on a higher place. * From hence the sea dipt everywhere above a degree below 

 us, the visible horizon being a lesser circle, and we saw Ireland plainly from the 

 W. b. S. to S. W. b. W. and the mountains of Cumberland or Westmoreland very 

 faintly, but evidently in the north ; and I think we saw as far as St. David's 

 Head into the south ; Carnarvonshire and Anglesey lay under us, like a map, 

 affording a very pleasant prospect, were it not for the horrors of the neighbour- 

 ina; precipices. Hence we counted 15 or l6 lakes, great and small, where the 

 cavities of the rocks ate filled up with the rills that gleet from the hills ; all these 

 are said to abound with trouts, some of which we found to be very good fish : 

 and in one of these lakes I was on board a floating island, as it may be called ; 

 the lake is scarcely half a mile about, environed with a boggy turfy soil, a piece 

 of which, about 6 yards long and 4 broad, floats on the water, being about 5 

 or 6 inches raised above it, but I believe about 18 inches deep within the water, 

 having broad spreading fungous roots on its sides, the lightness of which buoys 

 it up. It was driven on the lee shore, but I launched it off and swam it, to be 

 satisfied it floated : this I take the more notice of, because it is denied to be 

 true, by the author of the additions to Cambden, lately published : but I my- 

 self saw it as described, and was told it had formerly been larger, there being a 

 lesser spot, which they told us had been heretofore a part of it, which floated 

 likewise. 



Account of a Book, viz. — Nouveaux Memoires sur V Etat present de la Chine, par 

 le R. P. Louis le Comte, de la Campagnie de Jesus, Mathemnticien du Roy, 

 enrichi de Figures, ^msterd. 1697, in I'lmo, 2 Vols, and since translated into 

 English, and printed in 8vo. N° 229, p. 585. 



This book contains a great number of curious particulars relating to the em- 

 pire of China, with the travels of the missionaries in that wonderful country. 

 Its extent is from Canton to Pekin, N. and S. 18°, or '150 leagues; as much 

 from E. to W. and nearly round in figure ; so that it is near 1400 leagues about : 

 55° are the limits settled between Muscovy and Tartary, by the treaty of peace 

 between those kingdoms ; so that there are QOO leagues counting 25 to a de- 

 gree, of extent from the S. point of the isle Haynan to the extremity of Tartary, 

 ubject to China. In the journey to Pekin they met ice in the canals, and the 

 rivers were frozen. Here is an account of Father Verbiest, and his death in 



* Ihis comparison cannot be very accurate, owing to the want of regulation and correction by the 

 thermometer. We shall find occasions hereafter of more accurate comparisons. 



