Harmony man

Science and Culture (University of Chicago Press, £14.25/$17.95, ISBN 0 226 32659 4) reprints 15 lectures given by one of the earliest popularisers of science – and the inventor of the ophthalmoscope – Hermann von Helmholtz. Nineteenth-century German audiences were riveted by discourses on harmony in music, vision, the planets and more. The effect is still strong.