Copy of draft letter, from Sir John Herschel to Henry Liddell Copy of draft letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Regrets he cannot attend the meeting to lay the stone of the new lecture room, nor can he take an active part in the lectures due to an attack of influenza. Would like his name added to the ordinary members [of the Slough Mechanics Institute]. 21 April 1848