This section is from the book "Soyer's Standard Cookery", by Nicolas Soyer. Also available from Amazon: Soyer's Standard Cookery.
Wash twelve or fifteen anchovies in cold water, and dry them thoroughly. Remove the fillets from the bones, pound them smoothly with three ounces of butter, rub the whole through a fine sieve, and put aside.
Take the bones from six anchovies, wash the fillets and dry them upon a cloth, pound them well in a mortar; add six ounces of fresh butter, mix well together, and proceed as in the last.
 
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