Machine blocking necessitates the use of metal blocks, which are cast either in iron, aluminium, or spelter from moulds made from the wooden blocks, so that if only machine blocking is intended, it is first necessary to make the wooden pattern. The various workings of these blocks will be described in the “Blocking” chapter. The wood block also affords the model for taking Plaster of Paris casts. When orders are large and the wood blocks are required all the time by the stiffener or blocker, plaster copies are made from it, so that the sewers may have something definite to work to. These are made in the usual plaster casting method, and are only intended for temporary use, their cheapness and quickness of completion as against the cost of wood being the reason for their adoption, for they will not stand the stiffening and blocking processes. A subsidiary kind of block, constructed of wood and metal, is used for such parts of a one-piece hat or bonnet that cannot be reproduced in wood alone. The “Pork Pie” turban, in fashion during the '60’s of the nineteenth century, had a close curl or brim standing only about half an inch away from the crown. (_See_ John Leech’s drawings in _Punch_ of that period.) No wood curler as thin in texture as the shape required would stand any prolonged stiffening and blocking, so instruments called “Tippers” were used for blocking this style of shape. They had a wooden spindle that could be put in the spindle socket, to which a piece of metal, iron, brass, or zinc was attached. This was in the form of a widish, short length scoop, and with it a workman could iron a close brim in sections. These “tippers” were made with varying curves, so that any kind of oval could be reproduced. The advent of two piece hats, where the crown is attached to the brim after blocking, has rendered these instruments nearly useless, as by this new arrangement the wood brim for such a shape can be made quite solid. [Illustration: Fig. 9 “TIPPER”] Blockmaking is one of the most important sections contributing to the straw trade, for the perfect reproduction of a model’s outline depends entirely on the accuracy of finish given to the blocks. CHAPTER IX HAND AND MACHINE SEWING The next stage in the evolution of a straw hat _made from plait_ is the sewing together of the material to form the necessary shape.