A set of instructions entitled 'Adjustment of the Mirrors of the 10 feet Telescope' relating to a Newtonian reflecting telescope. It is made up of 4 pages of instructions with diagrams relating to method required to adjust the mirrors in the telescope. This is a copy of a document sent to Dr Abraham Robertson by William Herschel, the manufacturer of the telescope, on 8th April 1813, but it is not know who copied it.