Instructions for Patent of Daniel Spill of Homerton ... for his invention of 'improvements in machinery or apparatus for propelling tramway cars and other vehicles upon rails ... n.d. [Patent for provisional protection issued 1873, 3650 Nov 8]. Principle of atmospheric engine and plenum or vacuum. Facsimile tied in green ribbon, 20pp, lacking two sheets diagrams, 33x21cm. [Spill & Maples].