Images of medieval bellows
This is a collection of all the medieval/dark age images of bellows that I know of. While the aim was to document double bellows for casting hearths, oddly there are no depictions of casting workshops, only blacksmiths and hand bellows to stoke fires for other purposes. The single goldsmith shown has a small single bellows, presumably for soldering.
There is plenty of incidental evidence for bellows at casting workshop in the form of stone and clay tuyers as well as the obvious need for high temperatures, and literary evidence (Theophilus- 12thC) indicates their use as well, so I believe a safe assumption is that the same type of bellows used for blacksmithing would be used for bronze casting.
Viking age depictions
Depictions of bellows in the Viking age. The Ramsund carving shows a smith with an anvil, tongs, and a set of double bellows with a tuyer.
The wood carving of Sigurd also shows a smith with a helper operating double bellows. Note the very high action and pleating of the leather sides which may indicate banding to keep the leather from billowing out.
Bellows - 13th century
Images of bellows from medieval manuscripts, 13th century. The center picture is of a goldsmith. Note the center ridge, the diminutive size, and what are presumably indications of nails around the perimiter.
Of interest as well are the 2 examples with square intake holes. With the exception of the goldsmith, these are taken from martyr scenes, and the bellows are probably of a type used to start fires, as opposed to smithing or metalwork.
Bellows - 14th century
Bellows in 14thc manuscripts. Most of these are from scenes of actual forges. It would appear that artists did not understand the mechanisms for pumping the bellows on the side-draft forges, as they all appear a jumbled mess or a simplistic line.
Note what appears to be a wood framed, double sided forge.
Interesting is the complete lack of air inlet holes. Is this simply an ommision by the artist, or are they on the bottom?
More from the 14th century
More 14th century images.
Bellows - 15th century
Bellows from medieval manuscripts, 15th century. Note again that many of these do not show air inlet holes on the top.
More 15th century
More 15th century examples.