Subject ASC0000bn4
The Intellectual observer.
v.5 (1864), Page 101 (1864)
Harvard University, MCZ, Ernst Mayr Library
BHL Page 39488244
Keywords
astronomy day/night cycle sun Sun Earth light daylight earth latitude long days short nights northern summer June 21st Tropic of Cancer horizon mid-day sunrise sunset equator meteorology midnight sun diagram hemisphere astrophysics diagram midnight Sun long days short nights northern summer