At 41 degrees south latitude, you would see seasonal changes of all of the southern hemisphere stars. The circumpolar ...

I then went to The Nautical Almanac, where a number of tables helped me compute the declination (similar to latitude) and Greenwich Hour Angle (similar to longitude) of Sirius on the celestial ...

But the basic principles behind celestial navigation are fairly straightforward. Here are a few examples that show how a sextant can be used to find location... Finding latitude is easy enough.