This section is from the book "The Steward's Handbook And Guide To Party Catering", by Jessup Whitehead. Also available from Amazon: Larousse Gastronomique.
This is the candy rock work used to build up ornamental pieces of confectionery and to sell as sponge candy; it can be made of all colors and flavors: Boil a pint of clarified sugar in a copper earthenware pan to the degree of crackled, (See Sugar Boiling) ," use no acid in the boiling of this; remove it from the fire, and well mix into it a tablespoonful of icing, by stirring it in briskly with your skimmer. As soon as the sugar and icing is well mixed, and rises up like froth, put it into a papered sieve, or into an oiled tin or mould, and when quite cold, break it in pieces. If you have not any icing ready made, mix some sifted loaf sugar with the white of an egg, until it is quite thick, put in a table-spoonful, and it will answer the purpose of icing. If you want it colored, mix the coloring in with the icing. " And now we come to the finest piece in the group, described in the catalogue as ' Stronghold Caske, in piped sugar ornamental work, on a rock made of (souffle) sugar.' Souffle' sugar - or as it was called in our young days, 'Queen's bread,' - always makes a good bed for an ornamental piece of this kind, and in this case greatly enhanced the beauty of the castle above." (See Hints on Sugar).