16 
GEOGRAPHIC TABLES AKD FORMULAS. 
[bull. 234. 
METHOD OF FIXHSTG A MERIDIAN AT ANY TIME BY HOUR 
ANGI.E. 
[Extracted from United States Land Survey Manual.] 
The annexed diagram (fig. 6) will show in their proper relation the 
various aspects of Polaris in its daily apparent motion around the 
north-polar point. 
This must be carefully studied, as the illustration of Table 1, for 
finding at any hour the hour angle and azimuth of Polaris, and the 
resulting meridian, at times when more direct methods are not available. 
Hour angle of Polaris. — In fig. 6 the full vertical line represents a 
portion of the meridian passing through the zenith Z (the point 
directly overhead), and intersecting the northern horizon at the north 
pioint N, from which, for surveying purposes, the azimuths of Polaris 
W.elong.6 
I I o \ ' < \ 
1\ 'vw: :J>\ re 
i^^:^i\^ 
.Northern 
18^of^.elang. 
56 
horiTion 
Fig. 6.— Aspects of Polaris. 
are reckoned east or west. The meridian is pointed out by the plumb 
line when it is in the same plane with the eye of the observer and 
Polaris on the meridian, and a visual representation is also seen in the 
vertical wire of the transit, when it covers the star on the meridian. 
When Polaris crosses the meridian it is said to culminate; above the 
