Memorandum, September, 1877 motion picture

Adhered to page 4 is a newspaper article entitled "About Microphone Receivers," dated April 28, 1888.
Memo was possibly inside envelope with "Bell Telephone Company" letterhead, with "Revolving Contact Receiver" written on front.
Lists his latest electrical discoveries and inventions circa 1877, including contact telephone, electric spark telephone, and telephonic transfer.