This post was written by Tabea Rude
Not many clocks can claim a major olfactory experience by nature of their operation, but this one must have done: the hydrogen clock by Pasquale Anderwalt (1806-1881).
It is mentioned from the early 1840s onwards in several German publications. Anderwalt was a mechanical engineer and worked in Trieste. He developed machines for agricultural use and received a privilege for improvements on windmills. In the 1850s, he was involved in finding and proposing solutions for the frequent shortages of drinking water in Trieste.
For that reason, he was sent to the 1851 World Exhibition in London, to find out what the department of hydraulics and the gathered experts from all over the world had to offer. He also brought his hydrogen clock for presentation. Quite a number of these curious hydrogen clocks survived. Some readers may have seen one of these on display in the Clockmakers Company Collection at theScience Museum. Another is found in the Vienna Clock Museum, with three further examples in museum storage in Vienna and Trieste.
All of them have this rough idea in common: The glass cylinder is filled with sulphuric acid, the owner adds zinc and closes the lid. The zinc then reacts with the sulphuric acid to hydrogen, pushing a piston upwards, which in turn rewinds the weight.
Anderwalt himself claims that 'one ounce of zinc will last the clock machine at least for a human life span'. Probably a very trendy machine in its time, it could definitely compete with other alternative power ideas and not-so-perpetual-motion-clocks. Articles about these have been published in a number of Austrian, Moravian, Italian as well as Bavarian newspapers and scientific reviews. It is not known how many of these objects exploded during use or how smelly they really were.