Sujet
The Time Ball, Royal Observatory, Greenwich, Fig. 2, 1845. Creator: Unknown.
Légende
The Time Ball, Royal Observatory, Greenwich, Fig. 2, 1845. 'The hour of one o'clock is announced by the descent of a large black ball, from the summit of a pole, which surmounts the northwestern turret of the Observatory; a position singularly favourable for its exhibition to mariners on their progress down the adjacent river Thames. The apparatus...may be said to consist of a hoist for raising the ball, a trigger and discharging gear for its liberation, and a clock, regulated by observation, for giving the required moment of time...Fig. 2. The Ball Turret, viewed from the top of the Observatory, with the ball down'. From "Illustrated London News", 1844, Vol V.
Crédit
Photo12/Heritage Images/The Print Collector
Notre référence
HRM21A06_336
Model release
NA
Property release
NA
Licence
Droits gérés
Format disponible
47,9Mo (2,7Mo) / 28,6cm x 42,0cm / 3377 x 4960 (300dpi)