| Description | In February 1797 the Court of Common Pleas ruled that there should be no new trial in the case of Boulton & Wattt versus Hornblower and Maberly, the jury having found in favour of Boulton & Watt. Jabez Hornblower and Stephen Maberly then sought to have the case re-tried by taking out a Writ of Error in the Court of Kings Bench. The hearing of the arguments by Justices Lord Kenyon, Ashurst, Grove and Lawrence began in November 1798, and continued through into January 1799. The judges unanimously upheld the previous verdict of the Court of Common Pleas, which had been reached in December 1796. This verdict in Kings Bench effectively established James Watt’s patent as valid. Hornblower and Maberly could have chosen to take their case to the House of Lords, but they did not pursue this course, and Boulton & Watt used the Kings Bench verdict in their legal actions against Cornish mines who were withholding premiums.
The arguments and proceedings in the Writ of Error were published in 1799 as part of "The Arguments of the Judges in Two Causes relating to the Letters Patent granted to James Watt, Engineer, for his Method of lessening the consumption of steam and fuel in fire engines" (MS 3147/2/50). Boulton & Watt evidently decided on this quickly, as their note to Mr. Rous of 27 Jan. 1799 states that "B & W mean to publish the whole of the Proceedings in the KB, but that need not prevent Mr. Rous from publishing his argument."
This bundle contains memoranda for the various arguments, and transcripts of the proceedings in Court.
For drawings of Hornblower and Maberly’s engines, see "Designs by William Murdock, Atmospheric and Other Engines, Drawings for Court Cases," Portfolios MS 3147/5/1353b and MS 3147/5/1354c. |