so late as 1811. On January 19, of that year, Herschel observed the nebula of Orion with it. This was one of his last observations.
The final disposition of the telescope is told in the following extract from a letter of Sir John Herschel's to Mr. Weld, Secretary of the Royal Society:
Collingwood, March 13, 1847.
... "In reply to your queries, respecting the forty-foot reflecting telescope constructed by my father, I have to state that King
George III. munificently defrayed the
entire cost of that instrument (including, of course, all preparatory cost in the nature of construction of tools, and of the apparatus for casting, grinding, and figuring the reflectors, of which two were constructed), at a total cost of £4,000. The woodwork of the telescope being so far decayed as to be dangerous, in the year 1839 I pulled it down, and piers were erected on which the tube was placed,
that being of iron and so well preserved, that, although not more than one-twentieth of an inch thick, when in the horizontal position it sustained within it all my family, and continues to sustain inclosed within it, to this day, not only the heavier of the two reflectors, but also all the more important portions of the machinery.... The other mirror and the rest of the polishing apparatus are on the premises. The iron grinding tools
