Aqueous Vapour Atmosphere. 121 
[The following Observations are added since the paper was read.] 
1821.—Observations on Helvellyn. 
July 9th. Weather gloomy, a breeze from the north. 
Ht. above the Temp. Dew- Temp. of 
He: MM. valley, inyds. of air. point. Water. 
4 P.M. Summit ........ B55 uit 50% SR ee — 
8 — Inthe Valley  0...-.56 0 49 we 
July 10th, 9A. Moers, Osersseee—e sessereed srsseees _ 
—o0m0—-- 
Observations on Great Gavel.* 
(*This is a bold mountain rising on the north side of the Gap (Stye- 
head) betwixt Wasdale and Borrowdale.) : 
Took a circuitous ascent from the road betwixt Borrow- 
dale and Buttermere. 
July 11th. Ht.above Der- 
went Lake, in 
H. M. yards, 
1 45 P.M.Pointed Y y99. 1. Air foggy with gleams 
Summitt alternately. Thermo- 
meter in a fog, 55°, 
laid on a rock 59°; soon 
after in a thick fog 50.° 
Temp. Dew- Temp. 
; of air, point. of wat. 
Summit 
4 TR Q e 
4 40 P.M.of Great ¢ 900......2. SOS Fccienech AG Fades seoverrri 
Gavel. 
Left the summit at 63 P. M.: evening fine and sunny. 
TE < cccavecevaee Well....|| BO caeane nan coc evers FO 482 
The Dew-point varied from 49% to 54° the ensuing week in the plains 
below. 
+ South of Honister Crag, having Buttermere and Crummock Lakes 
in view nearly in a line. 
¢ Thermometer held up in the flying mist ; but 56° laid on a rock. 
|| In descending from Stye-bead into Wasdale. 
Q 
