| Description | James Watt’s statement in the Bristol newspapers in 1782 of the six features of his steam engine which he considering his exclusively put Jonathan Hornblower in a difficult position. His engines clearly used five of the features that Watt listed, and therefore his engines infringed Watt’s patent. Hornblower could not therefore erect engines under his own patent of 1781 until Watt’s had expired. However, Hornblower’s patent was only protected for fourteen years, whereas Watt’s was protected until 1800 by the Act of Parliament of 1775 which extended it. Therefore in 1791 Hornblower applied to Parliament to have his own patent extended. Boulton & Watt mounted a campaign of opposition to Hornblower’s bill, and he did not get his extension. He formally withdrew his bill in May 1792. However Boulton & Watt never took any specific action in the courts to prove that Jonathan Hornblower’s engines infringed Watt’s patent, despite the fact that orders for Hornblower’s engines were increasing.
This bundle contains a copy of Hornblower’s bill, and copies of the printed statements produced by both Hornblower and Boulton & Watt to support their arguments before the House of Commons.
For papers relating to premiums demanded from mines that erected Hornblower’s engines, see the bundles of papers relating to Cornish Law Cases (MS 3147/2/51—MS 3147/2/60). For drawings of Jonathan Hornblower’s engines, see "Sketches and Descriptions of Pirate and Rival Engines" (MS 3147/2/62) and "Drawings of Engine Designs by James Watt, Bull and Hornblower’s Engines, Dutch Windmill etc.", Portfolio MS 3147/5/1339c. |