Letter, from George Biddell Airy to Sir John Herschel, dated at Observatory, Cambridge Autograph letter signed by sender. Observations on the weather of the past winter. 42 Virginis. Printing of [Stephen] Groombridge's catalogue. Has written article for the Penny Cyclopaedia. Refracted light in prisms. Machine for polarization of the sky. Petition to Parliament to abolish religious tests for degrees at Cambridge. 24 April 1834