Winter solstice one must be able to observe a change in azimuth or elevation less than or equal to about 1/60 of the angular diameter of the sun. Observing that it occurred within a two-day period is easier, requiring an observation precision of only about 1/16 of the angular diameter of the sun. Thus, many observations are of the day of the solstice rather than the instant. This is often done by observing the sunrise and sunset or using an astronomically aligned instrument that allows a ray of light to be cast on a certain point around that time. Length of day
Three Months in the Southern States Three Months in the Southern States Three Months in the Southern States is a book written by Captain Arthur Fremantle, of the Coldstream Guards, upon his return to England from his three-month stay (April 2 until July 16, 1863) in the Confederate States of America. Most specifically mentioned in the book are Fremantle's travels through Texas, the deep south, and finally when he arrived in the company of the Army of Northern Virginia on June 27, and witnessed the Battle of Gettysburg firsthand, as part of a cadre of foreign observers attached to the headquarters of Lt. Gen. James Longstreet.