SUPPLEMENTARY REPORT ON METEOROLOGY. 151 
mula, (175, 180)), the absolute and relative dryness of the 
air, 7.e. the tension of vapour and the ratio to saturation. 
Experiments would still be desirable to ascertain the effect 
of a current of air in modifying the indications of the 
moistened thermometer. 
11. To pursue experiments on rain-gauges at three stations 
vertically above one another, (221) combined with hy- 
grometric observations. 
12. To deduce from phenomena proofs of the revolving or 
radiating character of storms, or of the existence of both 
kinds*. (212, &c.) 
13. To multiply observations upon meteors, especially in 
August and November. For this purpose, nothing more 
is requisite than the combination of several intelligent 
observers, who should select particular portions of the 
heavens for observation, having acquired, by the aid of 
a globe or planisphere a sufficient knowledge of the con- 
stellations, and who, being each provided with chro- 
nometers, should note, (1) the time of appearance; (2) 
the duration of the meteor; (3) its magnitude and phy- 
sical peculiarities ; (4) its direction and velocity of motion. 
14, From what has been said on the subject of atmospheric 
electricity, it will appear that almost everything remains 
to be done on that subject; he who proposes to enter on 
the field must be prepared to cope with the difficulties of 
original investigation. 
15. Auroral phenomena. The division of them into classes 
(if possible), of which probably the height, nature, and 
magnetic effects may be very different. 
16. Many of the departments of optical meteorology are well 
fitted for Sedentary Observation. See the particulars spe- 
cified in the next section. 
C. Travelling Observations. 
336. A traveller is placed in circumstances so eminently fa- 
vourable for arriving at just conclusions in meteorology and other 
similarly-conditioned sciences, that he cannot be too frequently 
reminded of the responsibility which attaches to his situation. 
All men who have cultivated the valuable art of viewing intel- 
ligently what passes around them, may arrive at important de- 
ductions from the observations of the most monotonous and most 
* Observations of great value may be very simply made by noting the 
periods of sudden rise of wind, and especially the times when its direction 
changes most rapidly, and the nature of the change. Barometrical observations 
add to the value of these recorded facts. 
