A photograph of inmates of Pentonville Prison, London, sharpening tools at a grindstone, taken by Captain Lewis, probably of the Royal Engineers, in 1871. All three men wear prison uniform. One man turns the large grinding wheel as the other two sharpen tools on it. Pentonville Prison was designed by Sir Joshua Jebb (1793-1863) and completed in 1842. It was a model prison built according to Jeremy Bentham's (1748-1832) concept of the 'Panopticon', consisting of five blocks radiating from a central point.
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