Copy letter from an unknown correspondent, to Messrs Harrison & Sons 'In answer to your memo [memorandum] as to fig. [figure] 3 p274 in the accompanying sheet if the block is wood, please put in three types S, M, I, where I have marked them, and never mind the D. But if the block is zincograph, this cannot I suppose be well done, & in that case proceed with the printing, as the letters do not really very much matter'. 10 April 1891