Letter, from Frederick Howlett to Sir John Herschel, dated at St. Augustine's, Hurst Green Autograph letter signed by sender. Is grateful for his communication on the proposed solar eyepiece. Will call round on his way to town to ascertain if he can leave the manuscript with [Thomas?] Cooke, the instrument maker, so that he can have some idea of the work involved. James Nasmyth will pay attention to screen projection. 9 May 1864