Above fig shows that Sun is usually not exactly along meridian at local noon, i.e.
Morehead sundial will not show Sun due S at noon on most days. 2 reasons:
1. Earth's orbit is not circle, so Sun sometimes appears to move across
sky faster or slower than average.

2. Civil time jumps by 1 hr at edges of time zone. Ideally these
are 15 degs in longitude apart, but actually are adjusted to
e.g. put whole US state in 1 zone (sometimes impractical, e.g. Tenn.)

Ernest Shackleton's Disasterous Antarctic Expedition


On Jan 15, 1915, became trapped in sea ice ... and 9 months later their ship is crushed and sinks ...

... forcing the men to live on the ice until the pack drifts N and starts to break up. On April 9 1916 they
dragged their 3 lifeboats across the ice to open water, and sailed in storms to Elephant Island,
a tiny, glaciated island on the Antarctic Peninsula.

Shackleton realizes that they will die there, so takes their best lifeboat, 22 feet long,
and with 5 companions sails for whaling stations at South Georgia Island 800 miles away
across the stormy S. Atlantic.

The men left behind (including the photographer, Hurley) bravely send their companions
off.

His navigator, Frank Worsley, successfully gets them to S. Georgia after 17 stormy
days at sea and they land, after enduring a hurricane, on the wrong side of S. Georgia.
Use the applet elsewhere in these Web pages to navigate
yourself across the S. Atlantic.

On May 19 1916, Shackleton and 2 companions cross S. Georgia's glaciers in 36 hours of non-stop
walking and reach the whaling station. On August 30, using a Chilean steamer, Shackleton rescues
his men from Elephant Island, 22 months after leaving port for the S. Pole. All survived!