Sujet

The Time Ball, Royal Observatory, Greenwich, Fig. 7, 1844. Creator: Unknown.

Légende

The Time Ball, Royal Observatory, Greenwich, Fig. 7, 1844. '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'. From "Illustrated London News", 1844, Vol V.

Crédit

Photo12/Heritage Images/The Print Collector

Notre référence

HRM21A06_340

Model release

NA

Property release

NA

Licence

Droits gérés

Format disponible

62,6Mo (2,7Mo) / 37,3cm x 42,0cm / 4409 x 4960 (300dpi)

Mots clés

technology time British clock observatory Victorian century Britain cog cogs gears newspapers press concept mechanism gear B&W timepiece clockwork timekeeping 19th century black & white black and white B W nineteenth century Royal Observatory The Print Collector crank handle Greenwich Observatory Illustrated London News ILN newspaper engraving Unknown time ball