Description of the Tables. 
Ixiii 
The seventh column gives the readings, in inches and decimals, of the Obser- 
vatory rain-gauge, made at noon. 
The eighth column contains the maximum pressure of wind on a square foot 
of surface which has occurred since the previous observation, No. 95. 
The ninth column contains the greatest pressure which occurs within 10 minutes 
at the time of observation ; titled the present pressure ; this is sometimes higher 
than the maximum previously recorded. 
The tenth column gives the point of the compass from which the surface-wind 
blows, as observed on the vane-dial. 
The eleventh column gives the points of the compass from which the clouds 
move, observed as described No. 97 ; when there are more motions than one ob- 
served, the motion of the lowest stratum of clouds is placed first, that is to say, next 
to the motion of the surface-wind in the tenth column ; the motion of the next higher 
stratum is separated from that of the lower stratum by a colon (:), and so with those 
higher still. Thus, July 12 a 18 h , while the motion of the surface-current was pro- 
bably from WSW., the lowest stratum of clouds moved from NW., the next higher 
from NNW., and the highest clouds from SE. by S. 
The twelfth column gives the estimated quantity of the sky covered with clouds, 
or the estimated surface of clouds compared with that of the whole hemisphere, the 
latter being 10. 
109. The page opposite to these columns contains the species of clouds and 
general observations on the state of the sky or weather, as observed immediately 
after the observations of the meteorological instruments. The clouds whose motions 
have been defined are placed first, commencing with the lowest, and when several 
motions have been observed the strata are separated, as the directions are in the 
eleventh column, by colons (:) ; thus, in the above example, July 12 d 18 h . Scud 
moved from NW., cirro-cumulous scud from NNW., and cirri from SE. by S. 
When the directions in which any clouds move have not been determined, these are 
separated from the others by a cross ~i— ; in the previous example there was a thick 
mass of cirrous haze and cumulo-strati to E., whose motion was undetermined. The 
initial of the observer is given last ; and as the same person makes the magnetical 
and meteorological observations, the initials serve for the magnetical observations 
at the same hours. 
Ternv-Day and Extra Meteorological Observations, pages 200 — 217. 
110. These observations are made, during the magnetical term-days, at the 
solstices and equinoxes,* and on other occasions. 
* The observations at the solstices and equinoxes were forwarded by Sir Thomas Brisbane to 
M. Quetelet of Brussels, and have appeared in his collection of " Observations des Phenomenes Perio- 
diques," Memoires de l'Academie Royale de Bruxelles. 
