Top Motions.
In [Plate VI.] are shown a number of top motions to keep the healds tight when worked from below. Each is self-explanatory, and by imagining the effect of changing the heald or healds which are up for others, the value of each arrangement will be seen. For example—take H, a 3-shaft motion, two up. If No. 2 be required up and No. 3 down, the change is made without any movement of the top pulley; if No. 1 be required down and the other two up, it will be drawn down a distance equal to the size of the shed—say 2 inches; whilst the small pulley being connected to a step pulley on the larger one, is only lifted half that distance—say 1 inch. Now, if the small one be raised 1 inch and No. 3 heald be kept still, No. 2 heald will lift 2 inches—the height desired.
It will be noted that a top motion is adapted only for one number of healds, and that the same number must be up in successive picks. Should different numbers be up at consecutive picks, a spring top as at S is used.
CHAPTER V.
COTTON CLOTH, CLOTH-LOOKING, VARIETIES, DIMENSIONS, STANDARD MAKES.
It is for export that the bulk of cotton goods are manufactured, for although the home trade is extensive when considered separately, yet if compared with the foreign trade it becomes unimportant. Goods for export may be classed into a few standard makes of cloth distinguished by some special feature as to length, yarns, finish or other characteristics such as are described later.
Before leaving the mill, the classification of the goods by name receives no attention, the order to which they belong being the only distinguishing description.