Royal Philatelic Society London: Sealing and Securing the Letter

This talk by the Royal Philatelic Society of London covers the approximate 40 year period from about 1820 to the 1860s during which the messy and awkward practice of sealing a folded letter (entire) with a wax seal was transformed via the introduction of wafer seals and the regular use of gummed envelopes during the 1850s.