<1841> <1>Friday morning
Mr Pim presents his Compliments to Mr Fox Talbot & begs to inform him that there will be a trial of the Atmospheric Railway on Wormwood Scrubs tomorrow Saturday at 2 o’clock
1. WHFT was interested in atmospheric railways. Instead of a steam engine dragging its own weight around, including fuel and water, this system employed stationary pumps that pressurised a cast iron tube laid between the rails. A piston set in the tube was attached to the railcar and propelled it along by air pressure. This idea excited tremendous interest in the newly developing railways and was initially successful. WHFT worked on the concept at least by 6th September 1840 (see Larry J Schaaf, Records of the Dawn of Photography: Talbot’s Notebooks P & Q (Cambridge: Cambridge University Press, 1996). The most promising system was conceived by the marine engineers Joseph and Jacob Samuda, who developed Samuel Clegg’s idea and persuaded I. K. Brunel to use it for his South Devon line. They had secured a patent for this in 1839 and started trials on a dis-used half-mile track at Wormwood Scrubs in June 1840. James Pim, a member of a Quaker banking family, promoted the employment of atmospheric propulsion for the Dublin and Kingstown Railway. He started attending the Wormwood Scrubs trials in the summer of 1841 and invited prominent scientific witnesses. Probably WHFT was invited to one of these, possibly as late as 1842, when the trials were concluded. See Charles Hadfield, Atmospheric Railways: A Victorian Venture in Silent Speed (New Abbot: David & Charles, 1967).