384 Scientific Intelligence. [Mar, 
of (viz. gauze wire) to prevent the combustion of the inflammable 
gases which abound there; why, let me ask, may it not be 
employed to the end proposed? It is an ascertained fact that 
the miasmata which stagnant waters exhale is diverted by the ~ 
mtervention of a few shrubs only.* It is also well known that 
travellers are preserved from the suffocating heat of the sinoc of 
the desert by merely bringiug their faces in contact with the 
surrounding sand, the minute particles of which, in all proba- 
bil, prevent the vapour from penetrating to the respiratory 
org: 9s. Thus we find that all media exhibit the same pheno- 
mena when opposed by the same difficulties; and, as far as 
reasoning from analogy will admit an inference, I cannot help 
subscribing to the belief of the practicability of what I propose. 
I beg leave, however, to submit it with great deference to the 
readers of the Amals of Philosophy, sincerely hoping that 
should they deen it worthy of experiment, the result will be 
successful, since it would tend so materially to the advancement 
ef the happiness of mankind. 
i have the honour to be, Sir, 
Your very obedient servant, 
J. M. BartTierr. 
X. On the Lunar Atmosphere. By Mr. Emmett. 
Hull, Feb. 15, 1819. 
On Dec. 5, 1818, about 11 o'clock, the moon eclipsed a 
small star in the constellation Pisces, when the’ 
followmg appearances were observed. S’ mM 
being the illuminated part of the moon’s disc, S’ 
the northern cusp, 8 8’ y the apparent path of the 
star; the contact took place at S’, and since the 
moon’s latitude was about 2°41’ S descending, the 
star was obscured for a very short space of time, the apparent path 
of the star cutting off'a very small portion from the moon’s disc :+ 
the star did not disappear instantly, as is always the case when 
the stars’ path approaches nearer the moon’s centre, but conti- 
nued in contact with the moon’s limb for 25” of time ; for five or 
six seconds it gradually lost some of its brilliancy ; then the form of 
a regular disc ; then appeared like a minute ray of bluish heght, - 
slowly moving along the moon’s limb, losing more of its brilliancy 
every moment, till at the end of about 25”, it disappeared in the 
most gradual manner. The star appears to have been kept in 
* OF this the Pontine marshes near Rome afford indubitable evidence, since 
whole families have resided near the spot for years without having suffered from 
the mephitic vapours which those putrid waters engender, and for which no other 
cause can be assigned than that a screen of érees separates their abodes from those 
pestilential wastes, 
+ A bare inspection ef the figure is sufficient to show that the minute effect of 
refraction through an atmosphere of very litle density, can only be observed when 
the versed sine of-half the are S’t.is very small; when S/ ¢ does not amount to more 
than 3° or 4°, the star must appear upon the limb for a considerable time, if the 
moon have av atmosphere capable of refracting light, ; 
. 
