‘Observation’ historical pictures (exact matches)

Discovering Our Cities: The Marvel of the Mersey (Liverpool). Jeremiah Horrocks.
Discovering Our Cities: The Marvel of the Mersey (Liverpool). Jeremiah Horrocks.
Il Presidente della Repubblica Francese alla fronte italiana
Il Presidente della Repubblica Francese alla fronte italiana
In 1911, Lt Giulip Gavotti became the first man to drop a bomb from a plane
In 1911, Lt Giulip Gavotti became the first man to drop a bomb from a plane
Claudius Ptolemy, Greco-Roman astronomer and mathematician and geographer
Claudius Ptolemy, Greco-Roman astronomer and mathematician and geographer
Percival Lowell
Percival Lowell
Observation balloon ascending, World War I
Observation balloon ascending, World War I
Chicago World's Fair, night view from observation platform of Sky Ridge
Chicago World's Fair, night view from observation platform of Sky Ridge
Bulletin de la Société belge d'astronomie
Bulletin de la Société belge d'astronomie