This image illustrates the French structure and techniques for manufacturing cod liver oil. Baskets of livers were carried from the stages to these devices and dropped down into a large rendering vat/container. The boughs woven around the outside kept the vat cooler while the long thin pieces of timber were used to guide the livers down and into the vat. There is one being constructed to the right. The small barrels in the picture were used to transport the finished product.
