The Tempest Prognosticator

The third research post from RCA History of Design students involved in the Memories of the Future exhibition (more information here).


A machine that predicts the weather using slimy invertebrates might seem an unusual invention to come out of the Victorian era. Yet, in 1851, Whitby physician George Merryweather completed his Tempest Prognosticator, a machine that relied on the instinct of leeches to forecast approaching storms and weather disturbances. The machine was made up of 12 bottles arranged in a circle around a bell fitted above. Each bottle was attached to a small hammer, loosely tied to a whalebone. Each bottle contained a live leech which when agitated by the weather, climbed to the top of the bottle and dislodged the whalebone to ring the bell.

The object may have been shown at 1851 Great Exhibition, the ‘successful predecessor’, but its failure makes it an interesting consideration alongside the visit1862 project. Why did Victorian society shun this object despite evidence of its success? This was not so much a question that needs to be answered as starting point for looking at the object and Victorian mentality.

Working Replica of The Tempest Prognosticator or Leech Barometer © Whitby Museum

Working Replica of The Tempest Prognosticator or Leech Barometer © Whitby Museum

One might simply conclude that the object was out of place in time, amongst a Victorian preoccupation with mechanisation and productivity and eight years before Darwin’s theories would be published and take hold. On the surface, perhaps, the idea that the lowly leech could be more intuitive than a man does seem reason enough for the Victorians to have dismissed it. On the other hand, the theory that would be accepted less than a decade later might also suggest that the primitiveness of the leech was precisely what would allow it greater powers in perceiving nature. (Would Merryweather’s machine then have been more successful in 1862?)

In any case, Merryweather’s fascination with animal instinct was not atypical of the Victorian mind. In fact, Merryweather was himself inspired by the eighteenth-century poet William Cowper who wrote to his cousin of the ‘prophetic powers of his pet leech’.

“I have a leech in a bottle that foretells all these prodigies ad convulsions of Nature… no change in the weather surprises him, he is worth all the barometers in the world.” [1]

Katherine Anderson’s study of Victoria meteorology suggests that these were popular ideas of weather wisdom typically attributed to sailor and shepherds and others who were adept in reading these signs. Victorian literature represents such figures prolifically such as Thomas Hardy’s Gabriel Oak to whom ‘the appearance of toads, and spiders from the thatched roof, slugs crawling indoors, indicated that the storm would be followed by cold continuous rain’. These are strikingly Romantic notions, no doubt. It is interesting to consider Romanticism with regards to this object and 1851, just a year after what is conventionally referred to as the peak period of the Romantic Movement. (Playing devil’s advocate- maybe the invention would actually have been more successful 10 years earlier? Did the machine just miss its moment?)

Merryweather’s machine may fit more easily in a literary history and tradition than a scientific one. This is not to say that this is where it belongs or that science has nothing to do with it. On the contrary, Anderson describes the Tempest Prognosticator as ‘a hybrid product, a combination of telegraphy and meteorological instrument that appeared to produce a special kind of instant sensibility’. So, empirical science and mechanics meet Romantic sensibility in a machine that attempts to read nature in the activity of leeches. This attests to the multi-layeredness and complexity of investigating an object. I found it interesting to consider the social context in this way and to consider the objects place in time. Not to trivialise the complexities of expositions, but to consider temporality as an important and contributing factor. How might 10 years (either in the past or future) have made a difference to the machine’s reception? What happened in the 10+ years following the highly successful Great Exhibition that made the 1862 International Exhibition a relative failure? Is it all a matter of timing?

[1] Cowper, William. (1874). Prognostications by Leeches. Chambers’s Journal of Popular Literature, Science and Art. 4 (Popular Science), 239.

Recommended Reading

William Cowper (1874), ‘Prognostications by Leeches’, Chambers’s Journal of Popular Literature, Science and Art. 4 (Popular Science)

Thomas Hardy (2002), Far from the Maddening Crowd. Oxford: Oxford University Press

Katharine Anderson (2005), ‘Maps. Instruments and Weather Wisdom’, Predicting the Weather: Victorians and the Science of Meterology (Chicago: University of Chicago Press) 171-234

© Oyin Akande, History of Design MA student, Royal College of Art and Victoria and Albert Museum, 2016

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