Mathematical drawing in pencil and ink, the central scale line is in pencil with curves drawn either side in ink with faint intersection lines drawn in pencil. The paper had been folded in half.
Inscription: Inscribed by Ostroff with: '23377'. Pencil drawing of a spectrum with a wrapper in Sir David Brewster's handwriting and inscribed with 'Place E6/ Place [?]/ In the Spectrum'. Originally mounted on a piece of card inscribed with '1832-DB'.
Inscription: Inscribed on recto: 'W.H.F. Talbot's Patent No. 1046'. Handwritten on verso: 'Talbot's Duplicate'. Four hand-coloured diagrams depicting the machinery to Talbot's patent for obtaining motive power.