76 



A NA TOMICAL TECHNOL OGY. 



B. Rust should be removed with a dull knife and then the 

 polishing may be done as above. When an instrument is badly 

 tarnished, the polishing with rouge is a tedious process. In that 

 case, fine emery may be used to remove the tarnish, and then rouge 

 for the final polish. The emery should be applied as directed for 

 rouge. 



C. If one has access to a polishing wheel the process is shortened greatly. The 

 same materials are used as in polishing by hand and in the same order. 



D. Emery of exceeding fineness may be easily prepared as follows : Fill a high narrow 

 vessel like a preserving jar, nearly full of water, and put into it about 200 grammes of 

 ordinary flour of emery. Agitate thoroughly, and after the vessel has stood half a minute 

 pour off the liquid into another dish. Add more water to the first vessel and agitate again, 

 and pour off the liquid as before. The larger particles sink first, and hence the emery in 

 the water poured off is much finer than that left. Allow the emery to settle from the first 

 and second washings and pour off the water and dry the emery. Several grades may be 

 obtained in this simple way. 



E. Instruments may be very nicely polished by using, in place of rouge, the fine 

 whitish ashes that may be found in the upper parts of stoves in which anthracite coal is 

 burned. 



F. If rouge is added to the oiled leather used for wiping the instruments after they 

 are washed ( 178), the polish may be retained indefinitely. 



SHARPENING INSTRUMENTS. 



184. Honing. For honing, it is desirable to have two oil 

 stones, one very fine for finishing, and one somewhat coarser for 



Turning knife. 



Honing. 



Stropping. 



FIG 28. HONING AND STROPPING KNIVES. The upper figure shows how the knife is 

 to be turned upon its back in reversing the movement. The left figure shows the 

 edge ward movement of the blade in honing; the right, the backward movement in 

 stropping. g 184, 185. 



