This bright Kelp seaweed was washed up in the Orkneys

Kelp used to be a big resource on those remote northern islands in the 18th and 19th centuries. Huge quantities were gathered from the shore after storms had battered the islands, and it was burnt to make ash. This was then used as fertiliser and in the soap and glass industries.

Each kelp fire burned from four to eight hours, assisted by quantities of heather and hay.

The fire was watched constantly by the womenfolk, who ensured it was kept burning steadily. When the blaze was going well, the menfolk would pound the seaweed in the fire, before covering it with stones and turf and leaving it overnight.

The next morning, the chunks of kelp ash were cool enough to be broken into lumps and transported south.

The Orcadian crofters toiled at kelp burning between the months of June and August to subsidise their work on the land.

Undoubtedly hard and backbreaking work, the kelp industry not only caused the health of the workers to suffer but in later years the land became neglected because the lairds had all the islanders working at the kelp.
(source: http://www.orkneyjar.com/tradition/kelpburning.htm)

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