Stuart Turner non-model engineering
Stuart Turner's Ltd.'s interest in all forms of small engines and simple devices that they might drive led to the production of a range of portable power plants and generators, and a highly successful range of small boat engines.
Domestic water supply pumps
Suart Turner Ltd.'s interest in centrifugal pumps (simple, shaft-driven) led to what later became the main product line of the engineering part of the business.
Centrifugal pumps have limited applications compared to piston pumps: although they can shift a lot of water smoothly across a limited height, they are not so good at drawing water in. A centrifugal pump throws water outwards using a spinning disc after which it's collected and sent through the output pipe, but its operation depends on there already being water in the system – a "dry" centrifugal pump doesn't do so much.
Where piston pumps can work with air or water, and produce a strong vacuum to suck water into the system (useful if you're using it with a long inlet hose), the need to fill a centrifugal pump with water before it could operate properly tended to restrict it to use with fountains and fishtanks (where the pump could be below water level), and other situations where there was already some sort of water pressure at the inlet. If you connected a centrifugal pump to your bath tap (or plumbed it in), it could boost the existing pressure, which was great if you lived in a flat with an unpressurised boiler at "person height" capable of feeding hot water to waist-high sink taps and bathtaps, but that couldn't let the water run uphill, to above head height, to work a standing shower. This led to the "killer application" for centrifugal pumps - the simple, reliable, cheap "power shower".