( ; ) 
thefe things muff, and fhali (God willing) be better 
inquired into. 
Next Summer come Twelvemoutb, I intend to try 
the Barometer and Thermometer on the Top of Snow- 
don and Cader Idris , and to take their perpendicular 
Height, and do any thing elfe that you (hall advife, 
which may be done conveniently. 
- There is noBrimftone or Pumice-ftones on the Tops 
of our Mountains, nor any thing elfe that I fufpeft to 
have been the Effects of Vulcano’s. What feemed to 
me moft ftrange, were wafle confus’d Stones, and (ro 
appearance) fragments of Rocks, Banding on the Surface 
of the Earth, not only in wide Plains, but on the Sum- 
mits alfo of the higheft Mountains. 
I have never feen any Lake or Spring on the Summit 
of a Hill. There are indeed on the tops of fome Hills, 
where flood anciently Cattles or Forts, certain Wells 
called in Wel(h Pydevo 3 a Word of the fame Significa- 
tion as well as Sound with the Latin Puteas : But no 
Water runs out of thefe 3 and feveral of them I found 
quite dry. I am, 
<SV>, 
Tour mofi obliged humble Servant , 
E. LHWYD. 
S ff 
V« An 
