462 Mr. Fallows’s catalogue of southern stars . 
The altitude and azimuth circle was made by Mr. Rams- 
den, and originally used as an equatorial instrument. The 
diameter of the vertical circle is 30 inches. The telescope, 
with two micrometers attached to the object and eye ends 
revolves, the circle itself being fixed to the upright axis. 
The frame is made of iron, and strongly screwed to a large 
block of stone (weighing about two tons) imbedded in the 
ground, and resting upon a rock. I have not yet had occa- 
sion to use the azimuth circle, except merely for reversing 
the face of the vertical circle. One cause of imperfection in 
this instrument is the slight manner in which the micro- 
scopes are connected with the telescope, the supports being 
too weak, and consequently liable to bend and be thrown out 
of adjustment in elevating or depressing the telescope to any 
given object. I have felt this defect severely, but could not 
get it altogether remedied here ; still however I have some 
hopes ( from the great care and caution in the management 
of the instrument) that the declinations in the following 
Catalogue will not be found very inaccurate. 
The latitude of the Observatory was principally obtained 
from a great number of observations of a Aquilse (this star 
having nearly the same zenith distance at Greenwich and the 
Cape ) , and compared with its north polar distance, as given 
by Mr. Pond in the Nautical Almanack for 1822. I tried 
several other Greenwich stars, and found a slight difference 
of a few seconds in the results, some in excess, others in de- 
fect ; but this is no doubt the fault of my circle : it is however 
satisfactory to know, that the mean of all agreed to nearly 
one second with that deduced from a. Aquilas. Whatever 
error I may hereafter find in my latitude will of course 
