Spotted today by a friend of mine in Birr Castle, home of the Parsons family which had connections with the Grubbs and the Great Telescope, built with the assistance of Thomas Grubb, was this Howard Grubb Aplanatic No 5281. It has 8 1/2 inch x ? coverage. My friend could not manage to get the second number , 6 or 10? The aperture is of the wheel variety. I suspect that this is from the very late 1880s or very early 1890s.
William
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