It's not in the shed anymore, dragged it out today as it's on it's way to a new owner who has a collection of early stationary engines.
I am hoping someone may be able to advise what it may have been used for.
I saved it from being broken up for it's copper and brass by a local scrap dealer about 35 years ago, I just couldn't let him break it up as it should really be in a museum.
It's a Crompton DC dynamo serial no.6270, 70 Volt 25 Amp output at 1280 RPM and I believe it could well be pre 1900 but I have no idea what it would have been used for and whether it had been driven by steam, petrol or maybe waterwheel or what equipment would have run off the 70 Volt output.
Preston Services had a similar one a few years ago but it had 3 armature supports and was 110 Volt output.