H.W. Cowley & Co in Bolton built engines that were designed by the Edwards brothers.

-They made 2, 4, 6 and 8 horizontally-opposed cylinder engines. The first two were seen on Avro aircraft.

-The 2-cylinder engines gave 15 hp at 1,000 rpm. They were built from 1910 to 1914.

-The 4-cylinder gave 30 HP at 1,000 rpm (1910).

-The 6-cylinder delivered 45 hp, and was manufactured in 1911.

-The 8 -cylinder delivered 60 hp, and was built in 1911 as well. For the latter two there are no known applications.

-The first one, the two-cylinder, can be admired at the Windsor Museum and at the Science Museum in London.

From Appendix 10: H-W-Cowley was a builder of several light-aviation engine models, established in Bolton as indicated in the ad where where is shown the two-cylinder Cowley engine.

"Cowley ad"