Blisworth Limestone Formation today in the seas off the Bahamas (Kirkaldy p. 59). Much of it also contains marine shells, notably of oyster. Subsequently, the site was submerged less deeply so that the overlying Blisworth Clay was deposited in brackish conditions. (Gallois p. 20) The stratum is known as Blisworth Limestone because it was first studied at Blisworth in Northamptonshire when the Blisworth tunnel was being dug for what is now called the Grand Union Canal. The tunnel finally opened in 1805. Blisworth limestone is a generally thin but widely spread deposit in eastern England. It becomes thicker as one progresses southward from
Grand Junction Canal canal from the Thames reached Two Waters near Hemel Hempstead in 1798, Bulbourne at the north end of the Tring summit in 1799, and Stoke Bruerne at the south end of Blisworth Tunnel the following year. Thus, with the exception of Blisworth Tunnel, the main line was fully open in 1800. To allow goods to cross the gap, a road was built in 1800 over the top of Blisworth hill and, later, upon the recommendation of committee member Joseph Wilkes, Benjamin Outram was contracted to build a tramway over the hill. James Barnes proposed that work begin again on the