Despite that, however, his work-force were fiercely loyal, and hundreds of armed men were on instant call to defend the mill against the threat from machine breakers. Arkwright kept a cannon loaded with grapeshot just inside the main factory gate, to emphasise the point.
Arkwright's lasting achievement, perhaps, was in doing for cotton what others had done for silk - and with the potential market for cheap cotton products so much bigger, his efforts at Cromford, elsewhere in Derbyshire, and in Lancashire and Scotland inevitably triggered that quantum leap in national productivity that became known as the Industrial Revolution.
Historians have pointed out that, although his machinery ideas were "borrowed," Arkwright did at least invent the factory system, the organisation and regimentation of labour in one specialised workplace giving the employer total control over the product and the means and cost of production.
But even this was not strictly true. Factories - particularly silk mills - had existed in England for more than 50 years before Arkwright opened his first big mill at Cromford in Derbyshire in 1771.
At least, say his supporters, he was a benign, humane employer, but this, too, was true only in relative terms. Unlike others, Arkwright did refuse to employ children under the age of seven or eight, but that did not stop him building Cromford like a fortress and using clever, physchological techniques to keep his work-force in fear.
When Arkwright died at Rock House in 1792, he left a fortune estimated at £500,000. Maybe that doesn't sound much, but it's more than £200m in today's terms.