Toads and blasting powder
04 April, 2013
Last week took me to Crichton Castle, which sits on a ridge overlooking the valley of the Tyne. The river Tyne is lined by coppiced Alder. Coppicing is a method of cropping wood in which trees are felled at the base and allowed to re-grow then felled again every few years, coppiced trees tend to have many trunks. Historically the coppiced alder was made into charcoal, which was then used to supply the local gunpowder industry.
Scotland’s first gunpowder mill was built in 1794 on the banks of the Gore Water in Gorebridge a couple of miles from Crichton. The construction of the gunpowder mill was a major work of engineering for its time. The Gore Water was diverted, four dams were built and a complex system of lades operated ten water wheels which powered the various mills.
The mill supplied blasting powder for quarries and mines as well as gunpowder for military use. It is recorded that gunpowder was supplied to the army during the Napoleonic Wars. Working in a gunpowder mill was notoriously dangerous. At the near-by mill in Roslin Glen a newspaper recorded an explosion where ‘ … a dismembered hand of a worker was found clutching an iron tool.’ Iron tools were of course banned in the mill to prevent the generation of sparks, and the use of an iron tool would therefore have exonerated the mill owners from blame!
This week’s blog was supposed to be about the Holyrood Park rangers Easter event, the annual toad day. At this time of year the common toads normally leave their winter homes to make their way to ponds to mate. This year it has been so cold, the second coldest March on record, the toads are still hiding away from the weather. The toad event had to be postponed.
Holyrood Park isn’t the only Historic Scotland site with toads. The woodlands at Caerlaverock Castle contain many ponds, home to another sort of toad, the natterjack toad (thanks to SNH for the wonderful photograph above). This is a much rarer toad, than the ones found at Holyrood, and the south west of Scotland is their most northerly habitat in Britain,
The natterjack toad prefers small seasonal ponds, ponds which often dry out during the summer months. When this happens the tadpoles do die, however this is compensated by the ponds having relatively few predators compared to larger ponds. The natterjack toads also breed up to three times during the summer to ensure some surviving young. They have shorter legs which means they can run rather than hop or crawl like frogs or common toads. The natterjack is famous in the natural world for the males mating call, which can be heard up to two kilometres away.
Crichton Castle is well worth a visit. The façade of the Earl of Bothwell’s lodgings are particularly stunning. The castle is open 1 April – 30 September , every day, 9.30 am to 5.30 pm.