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What we've done is used plastic beads to take away the paint layers
which were put on during the recent restoration processes of the telescope.
What we can see here is remnants of the top black paint layer which, as you can see, is very, very thin.
There's almost nothing left on the surface in terms of thickness there.
And then we appear to have some sort of a red epoxy primer by the look of it,
which can be quite effective at stopping corrosion on this sort of surface.
So from that point of view they've done a good job.
What they haven't done on this particular object is to follow the traditional method of painting
where you would have a very, very thick paint layer onto the surface,
which tends to hide all of the machining marks and the flaws in the surface.
Being an 1880s casting, you'll see lots and lots of little porous spots in the cast iron,
which are the result of the casting technology.
Producing a piece of metal this size was quite difficult and it usually
had little air bubbles in the surface, which is what we get here.
So 1880s cast iron in particular is almost always covered in a very thick paint layer,
up to about one or two millimetres thick, to hide all of those flaws.
And what we can see on this paint layer is actually, through the paint, hints of the machining marks.
But when we've come back to the remnants of the original surface,
what we can see is little spot marks where the sandblaster'*** and caused a great deal of damage, unfortunately.
But underneath that damage we can actually see the original lines which were caused when this piece was machined,
probably in an early steam engine powered lathe which was driven off a belt.
And these actually give a very good indication of the way this particular piece of metal was manufactured.
What I can see here is a group of stop/start lines which are indicative of having to
stop and start the machine to resharpen the tool because they were using
very primitive steel tools, which would actually get blunt very, very quickly.
So the person making this piece of metal would have to machine about that far, go away for 20 minutes,
sharpen the tool again, and then come back and do another section,
and another section, and another section.