In 1856 Elliott Brothers, successors to Watkins & Hill, were instrument makers in London. At the 1862 International Exhibition they saw Charles. T. Porter's display of a high-speed steam engine, which included an example of Richards' patent steam engine indicator. This was the first indicator suitable for use with the new high-speed steam engines, and Elliott Bros. licensed the Richards patent and manufactured this indicator. They were the exclusive licensees.
In about 1888 the exclusive license to produce the Richards indicator went to Hannan & Buchanan of Glasgow. The Elliott Brothers firm, meanwhile, survived into the early 20th century.
Information Sources
- 1868 Description of Richards' Improved Steam-engine Indicator with Directions for Its Use. This treatise was written by Charles. T. Porter and that link is to the first edition. In 1873 a second edition was published, retitled to A Treatise on the Richards Steam-engine Indicator, Manufactured by the Elliott Brothers, London; we have not found this edition available online. In 1874 the Third edition was published and is available online, as linked (we have also seen Third editions dated 1880). The 1888 Fourth edition is also available online. In total there were at least six editions of this book, the 6th dating from 1902.