NICKEL-PLATING. 



137 



The single room of this factory has a rectangular shape, 

 measuring 50 feet long by 40 wide. It is divided into two 

 parts by means of a partition which separates the bath depart- 

 ment from the preparing and finishing departments. 



The machines a, b, c, are provided at each end of their 

 spindles with a brush used for polishing the pieces before and 

 after the nickel-plating. These brushes are made of pieces of 

 linen stuck over one another, and revolve at 2000 revolutions 

 per minute. The machines d (Fig. 23), the ends of the spindles 

 of which are terminated in points, are provided with hair brushes 



FIG. 25. 



Special Polishing Machine. 



revolving also at 2000 revolutions per minute, and are used for 

 polishing pieces having slight prominences. The machines e 

 are provided with a disk of the very hard sandstone known 

 under the name of grisard, and on the circumference of which 

 is stuck a leather band. This disk rotates at 1500 revolutions 



