346 MR. J. WELSH’S 
ACCOUNT OF METEOROLOGICAL OBSERVATIONS, ETC. 
Table IV. (Continued.) 
Hour. 
7 A.M 
9 
Noon 
3 P . M . 
9 
Barom. 
Therm. 
Dry. Wet, 
Tension 
of 
Vapour. 
Les Rousseaux, Aug. 17. 
29-475 
•456 
•395 
296 
67-1 
69-1 
76-7 
62-0 
63-1 
66-4 
80-8 68-2 
•297 i 70-5 67-3 
0-502 
•513 
•534 
•546 
•630 
Barom. 
ITierm. 
Dry. 
Wet. 
Tension ! | 
„ I] Barom. 
Vapour. 
Therm. ' Tension 
— \ of 
‘ Therm. Tension 
of 
Drv. 
, „ Barom. i t- 
Wet. Vapour. Dry. Wet. ' aponr. 
Les Rousseaux, Aug. 26. 
29*443 
•445 
•449 
•454 
•494 
63-1 
72-0 
78-8 
78-3 
67-8 
59-0 
61-3 
66- 9 
67 - 6 
63-0 
0-460 
•427 
•525 
•553 
•524 
Marboue, Oct. 21. 
Marboue, Nov. 10. 
29-752 
•752 
•691 
•667 
•635 
34-9 
52-0 
60-1 
59-2 
49-5 
32-7 
47-1 
53- 2 
54- 1 
46-8 
0-179 
•283 
•338 
•371 
•304 
29-719 43-0 41-2 
•703 49-3 46-4 
•668 57*6 52*7 
•650 56*3 50*7 
•628 ,44-6 41-9 
0*255 
•297 
•354 
•319 
•252 
Description of the Plates. 
PLATE XIX. XX. XXL and XXII. 
The results for each ascent of the observations of temperature, tension of vapour, 
and relative humidity are projected in these Plates. For the most part each 
individual observation is given, except when they were very numerous and occurring 
at too close intervals of height to be easily represented. In such cases groups have 
been taken, but no group ever contains more observations than were recorded within 
200 feet. ... 
The ordinates represent the height above the level of the sea, one division being 
equivalent to 200 feet ; the abscissae representing the temperature of the air, the 
tension of vapour, or the relative humidity. 
The scale employed for the temperature is one division to 2° Fahr. ; for the tension 
of vapour, ten divisions to 0*2 inch of pressure of mercury ; and for the relative 
humidity, twenty divisions to the whole range 0— 100. 
The straight lines drawn through the curves of temperature are deduced from the 
results of equation (1.) for the upper and lower divisions in each senes (see p. 25). 
The points O in the curves of tension of vapour are from the indications ot 
Regnault s hygrometer. 
In the divisions occupied by the relative humidity the strong vertical lines corre- 
spond to the heights at which clouds existed in the air, dotted lines being drawn 
when the cloud was only partial. 
