SUPPLEMENTARY REPORT ON METEOROLOGY. 113 
ginal approximation, we think that he has fully made out his 
main point ; for he has shown* that the value of the co-efficient 
m depends upon the dryness of the air, at least that it is very 
nearly inversely as the mean daily range at any season, a datum 
which, in a good degree, indicates the relative dryness ; although 
without direct hygrometrical experiments the investigation must 
be considered as incomplete. Mr. Phillips desires that these 
experiments should be further pursued at points where three 
rain stations, vertically above one another, can be procured, 
and he has given instructions for making such observationsy{. 
222. Prof. Bache, of Philadelphia, has shown the very mate- 
rial influence which the eddies of air surrounding a station, such 
as a tower or steeple, exert upon the fall of rain, depending on 
the position of the gauget. Mr. Phillips is at present engaged 
in an ingenious series of experiments, to estimate and elimi- 
nate these disturbances. 
223. An admirable list of rain-gauge experiments, in differ- 
ent parts of the earth’s surface, is given in Prof. Muncke’s ar- 
ticle on Rain, in Gehler’s Physikalisches Worterbuch§, an 
elaborate treatise, which appears to exhaust the literature of the 
subject. 
224, It appears from the Report of the Birmingham Meeting 
of the British Association, as given in the dtheneum journal ||, 
that doubt has been thrown upon the statement of the remark- 
able fall of rain cited in my former report]. I was not pre- 
sent at either of the discussions alluded to ; I therefore take this 
opportunity of stating the authority upon which these very sur- 
prising falls of rain were admitted into my report—authority 
so ample, that, as a historian of science, I could not have 
omitted them, improbable as they do most certainly appear. 
225. The fall of 30 inches of rain within 24 hours took place 
at Genoa** on the 25th October, 1822. An assertion to this ef- 
fect having appeared in a Genoese newspaper, the editors of the 
Bibliotheque Universelle wrote immediately to make the ne- 
cessary inquiries as to an observation so unprecedented. The 
reply, which they obtained from M. Pagano, “ observateur 
exact,” is given at length in this journal}7, and is, I think, by 
no means the less satisfactory because it was obtained by the 
most inartificial of rain-gauges :—‘‘ Deux sceaux de bois, presque 
cylindriques, dont l’un de vingt-quatre et l’autre de vingt- 
* British Association, Third Report, p. 410. 
T Ibid., 5th Rep., p. 178. t Ibid., Eighth Report, Sections, p. 25. 
§ Vol. vii. Part Il. p. 1309. Leipzig, 1834. 
|| 31st August, 1839, p. 658. q P. 252. 
** Not Geneva, as stated by a printer’s oversight in the former report; the 
MS. was correct. 
tt Vol. xxii., Partie Physique, p. 67. 
VOL. Ix. 1840. I 
