The picture above is the last in this series related to the repair of
the Parkes Master Equatorial drive system, and shows the reassembled
drive system with new worm gears in place. The blue colouring visible
is Engineer's blue, a temporary marker commonly used by machinists
and toolmakers, used to check the mesh of the gears after
installation. Vincent van Gogh used this pigment, known to artists as
Prussian blue, in his painting "Starry Night", and so its use in this
application for the telescope is quite appropriate!