Trade card of Bleuler, scientific instrument makers, 18th century.
© Science Museum / Science & Society Picture Library
Bleuler's premises were based at 27 Ludgate Street, London where they made mathematical, optical and philosophical instruments. The trade card illustrates a man and a boy using compases and dividers, with Bleuler's wares including an armillary sphere, a telescope, and a terrestial globe in the foreground. On the left men are erecting a lighting conductor, and the building on the right is probably the Royal Observatory at Greenwich.