OPERA METER

is the name given to an apparatus patented in February, 1829, by Samuel Walker, cloth manufacturer, in the parish of Leeds. It consists of a train of toothed wheels and pinions enclosed in a box, having indexes attached to the central arbor, like the hands of a clock, and a dial plate; whereby the number of rotations of a shaft projecting from the posterior part of the box is shown. If this shaft be connected by any convenient means to the working parts of a gig mill, shearing frame, or any other machinery of that kind for dre ing cloths, the number of rotations made by the operating machine will be exhibited by the indexes upon the dial plate of this apparatus. In dre ing cloths, it is often found that too little or too much work has been expended upon them, in consequence of the unskilfulne or inattention of the workmen. By the use of the opera meter, that evil will be avoided, as the master may regulate and prescribe beforehand by the dial the number of turns which the wheels should perform. A similar clock-work mechanism, called a counter , has been for a great many years employed in the cotton factories to indicate the number of revolutions of the main shaft of the mill, and of course the quantity of yarn that might or should be spun, or of cloth that might be woven in the power looms. A common pendulum or spring clock is commonly set up alongside of the counter; and sometimes the indexes of both are regulated to go together, when the mill performs its average work.