No summary available.
No summary available.
Describes prismatic spectrum of flame of cyanogen and offers to repeat experiment with Michael Faraday for JH's benefit.
Asks JH to clarify what goods are his from a joint order with WT from a German optical firm.
Queries and comments about telescopes and microscopes; some thoughts about a diffraction grating.
Renders an accounting of expenses for optical goods received from Germany.
Thanks WT for optical equipment sent. Notes death of Augustin Fresnel. Has purchased a telescope from James South.
Writes in favour of a London University professorship for Thomas Key. Refers to some optical experiments of Michael Faraday, and extends solution of conic section problem first raised in WT's letter of 1826-2-27.
Responds to WT's 1827-10-29. Sending JH's Light, which uses some of WT's publications.