People waiting in anticipation for the time ball to drop at the stroke of 13:00 GMT. The time ball allowed the ships on the river to synchronize their clocks that were so important in navigation as you can shoot as many stars as you want with a sextant, without the correct time the tables can't tell you your correct latitude.
Camera: Pentax MZ-3, lens: Sigma 24-70mm F2.8 EX DG MACRO