TRANSACTIONS OF THE SECTIONS. 37 
give birth to coloured crowns opposite the sun, a phenomenon which up to the pre- 
sent time remained unexplained. In support of views purely theoretical, which are 
developed at length, I bring first the experiments of Mr. Miller on threads of water 
of three different diameters, then the direct ubservations of Mr. Galle on the rainbow, 
afterwards my own experiments on very fine cylindrical threads of a viscous liquid, 
and finally, my observations on the coloured rainbows which are seen in cooled water, 
or on the irisation of the little cloud formed above hot water, 
All these facts justify, fully and in all its details, the theory which I have pro- 
pounded, and clearly show how illusory was the theory of the efficient rays of Des- 
cartes ; the latter facts, above all, are a proof of the fallacy of the hypothesis of the 
vesicular state. They teach us what is the true constitution of clouds and fogs 
whose temperature is beyond zero Centigrade, and it is the only principle of inter- 
ferences suitably employed which enabled me to establish it with certainty. 
Towards the close of my memoir, I call the attention of physicists to certain 
singular facts, not yet explained, of interferences produced by very thin lamine. I 
draw from these facts a most conclusive argument against the explanation which 
had been given of the suspension of the clouds by the hypothesis of vesicular vapours. 
For this reason, and for all the others which I have deduced against the truly singular 
hypothesis of the vesicular state, and against that of efficient rays, I dare hope these 
two hypotheses will be henceforward banished when teaching the sciences which they 
shackled; that they will never more be called to explain the suspension of clouds, the 
colours of the rainbow, the absence of the rainbow in clouds or fogs, but that we 
may confine ourselves to the explanations, free from every gratuitous supposition, 
which I have now given of these phenomena. 
Meteorological Phenomena at Huggate, Yorkshwe. 
By the Rev. T. RANKIN. 
On the Temperature of the Air registered at the ‘ Plover’s’ Winter-quarters 
at Point Barrow, in the Years 1852, 1853, 1854. By Joun Simpson, 
| MD. RN. F.R.GS. 
This communication was brought under the notice of the Section by Prof. 
Haughton. The author commenced by saying that his attention was first directed 
to the importance of this subject, and he was induced to undertake the laborious task 
of hourly observations on the temperature in these regions, by certain remarks of 
Sir J. Richardson, at p. 331 of the ninth volume of the Royal Geographical Society’s 
Journal, 1839, in referenee to Sir D. Brewster’s discussions of the hourly register 
of the temperature at Leith Fort. The author then stated that the observations had 
been continued from the 3rd of September, 1852, to the 7th of August, 1853, and 
for a few days before and after each of these dates in the neighbourhood, making a 
complete year, less 21 days; again, in precisely the same locality, from the 7th of 
September, 1853, to the 19th of July, 1854, to which have been added the first six 
days of September and one day, the 21st of July, during which the ship was in the 
_ immediate neighbourhood, making a second complete year, less 42 days. The ship 
returned to the same spot on the 27th of August, 1854, and remained four whole 
_ days, for which the hourly register gave a mean temperature of 39°-448, serving as 
a fair guide for estimating the temperature of the last eleven days of August. He 
then touched on the principle of an estimate for filling up the entire interval of twenty- 
one days in 1853, and proceeded to describe the instruments used, which were fur- 
nished by Adie and Co. of Edinburgh, and which, having been returned to the Hydro- 
grapher’s office in 1855, could now be re-examined and compared with standards at 
Kew. The author then proceeded to give some highly interesting details of the 
freezing of the mercurial thermometers, and of the freezing of mercury exposed in open 
vessels ; the temperature when it froze seemed about 39°. Prof. Haughton then pro- 
ceeded to direct the attention of the Section to several interesting pvints, selected 
from the Journal and Tables, and concluded by describing two large sheets of curves 
of mean temperature; Fig. 1 showing the mean daily curve of temperature in the 
y shade for each month of the year; also the mean daily curve of temperature in the 
sun for the month of June. Fig. 2 showed the mean daily curve of temperature for 
4 
_each season of the year for the summer and winter half-years, and for the whole year ; 
