1. Letter to Campbell MacPhail, Ellary Farm [The Wonder of Sound] Artist: Unknown (Unknown) Classification: Work on paper Materials: black and red offset printing on paper, and typewritten text on sticker in brown paper envelope with postmark and metered stamp Dimensions: sheet: 7 /3/8 x 7 1/4 in. (unfolded) Accession Number: 1995.46.312.a-b