28 
SURVIVAL ON LAND AND SEA 
overhead. From the horizon to that point is 90°. Halfway 
from the horizon to the zenith (the point overhead) would be 
45°, one-sixth (or one-third of half-way) would he 15°, and 
so on. 
Of course, 1 degree of latitude is 60 miles, so if you are 10 
degrees off in estimating the altitude of Polaris you will be 600 
miles off in your estimate of latitude. If you ever have to use 
this, measure the star’s altitude as exactly as you can — and then 
don’t place too much confidence in the accuracy of your estimate. 
Southern Cross 
In the Southern Hemisphere Polaris is not visible. There the 
Southern Cross is the most distinctive constellation. As you 
☆ 
Figure 7. — Southern Cross. 
