14.8 
Astronomical Societij* 
The high-main seam was first worked, then the Maudlin, and af- 
terwards the Hutton, and the removal of each was attended with a 
depression in the line of the railway. The extent of each settlement 
was not measured, but the whole amount was 5 feet 6 inches, the 
aggregate thickness of the seams being 14 feet 11 inches. This 
small effect Mr. Buddie explains by showing, that the railway passes 
near one end of the excavated tract, and that metal- stone predomi- 
nates over sandstone in the superincumbent strata. The working of 
the five- quarter seam is now in progress, and the effects occasioned 
by the removal of the three lower seams are well exposed. Innu- 
merable vertical cracks pass through the coal, its roof and pavement, 
but they are perfectly close except around the margin of the settle- 
ment. Along this line the strata are bent down, the cracks in the 
pavement are frequently open, forming considerable fissures, the coal 
is splintered, and the roof-stone is shattered. In the interior of the 
settlement the pavement is as level and smooth as if it had never been 
disturbed, and the cracks are quite close, passing through the sfeam 
without splintering it or producing any effect except that of render- 
ing it tougher, or, in the language of the colliers, “ woody.’’ This 
effect, Mr. Buddie conceives, may be attributed to the escape of the 
gas, and he states that it is sometimes produced by other operations, 
when the coal is said to be “ winded.” The smoothness of the pave- 
ment, he is of opinion, is due to the direct downward pressure of the 
superincumbent mass ; and he states, that he has never noticed any 
tendency to a sliding or sideway movement in any subsidence of 
strata occasioned by the working of the coal, except the slight ob- 
liquity occasioned % the offbreak at the sides of the settlement. 
[To be continued.] 
ROYAL ASTRONOMICAL SOCIETY. 
December 14, 1839. The following communications were read ~ 
On the parallax of Sirius. By Thomas Henderson, Esq. Astro- 
nomer Royal for Scotland. 
The parallax of Sirius, the brightest star in the heavens, has 
been several times the subject of investigation among astronomers. 
From the variations of the zenith distances observed at Paris, the 
second Otssini inferred a parallax in declination amounting to six 
seconds of space ; and, from similar variations in the observations of 
La Caille made at the Cape of Good Hope, some astronomers have 
deduced a parallax in declination of four seconds. Piazzi has also 
obtained from his observations a parallax of the same amount. On 
the other hand, La Caille’s observations of zenith distances made 
at Paris, more numerous and certain than those made at the Cape, 
do not exhibit any sensible parallax ; and the observations wLich 
have since been made in the observatories of Europe, would appear 
to lead to the same result, as no parallax has ever been deduced 
from them. In the Fundamenta Astronomice, M. Bessel has in- 
vestigated, from Bradley’s Observations of Differences of Right 
