1. Next, a long tapering round metal pricker was inserted so that its point penetrated a short distance into the powder.

2. The diameter of different parts of pricker is indicated by machine number. The smaller machine number means the larger diameter.

3. By 1873 it had become illegal to have in one's possession in the mine a ferrous metal pricker or scraper.

4. Comparison is done to the conventional carding machines regarding the pricker roller and the wire roller. Result shows that fiber is less damaged using the pricker roller instead of the wire roller.

5. The analysis is done to the mechanism of the less damage of the pricker roller. Conclusion is made that the tooth width of the wire may he the cause of the more damage of the wire roller.

6. The analysis is done to the mechanism of the less damage of the pricker roller. Conclusion is made that the tooth width of the wire may be the cause of the more damage of the wire roller.