Copy letter from Robert William Frederick Harrison, to Mr Louis Zettersten, 98 Great Russell Street, W.C. 'Dear Sir, Your enquiry about lectures by Colonel Balck has evidently been addressed here in error, as no such lectures are to be delivered here. Possibly your letter should have been addressed either to the Royal Institution, Albermarle Street, or to the Society of Arts, in John Street, Adelphi. I am, yours truly, Robt [Robert] Harrison'. 16 May 1906