Crowmarsh Gifford Norman. A north transept with a pointed arch was added in about 1200. The building was restored in 1836 and 1868. In 1139 King Stephen built a wooden fort in Crowmarsh, the first of a series built in opposition to Wallingford Castle, which supported his cousin Matilda during the civil war known as The Anarchy. The forts were probably dismantled as a result of the Treaty of Wallingford of 1153. The castle at Crowmarsh consisted of a wide ditch surrounding an enclosure measuring . In 1701 agriculturist Jethro Tull invented his revolutionary seed drill here. In 1770 nearby Mongewell Park
Down-the-hole drill for the DTH method underground, where the direction of drilling is generally upwards instead of downwards. In "DTH" drilling, the percussion mechanism – commonly called the hammer – is located directly behind the drill bit. The drill pipes transmit the necessary feed force and rotation to hammer and bit plus compressed air or fluids for the hammer and flushing of cuttings. The drill pipes are added to the drill string successively behind the hammer as the hole gets deeper. The piston strikes the impact surface of the bit directly, while the hammer casing gives straight and stable guidance of the