62 



THE AMERICAN MONTHLY 



[April, 



diamond drawn along cuts off a 

 strip of the glass just one inch 

 wide. Care must be taken that it 

 is the point of the diamond and not 

 the edge of the rule that is just an 

 inch from cleat A, or the slide will 

 be too narrow. The track of the 

 diamond is indicated by the dotted 

 line D. In this manner strip after 

 strip of glass is cut from the ori- 

 ginal piece three inches wide until it 

 is cut up into slides of an exact 

 width. Care should be taken that 

 the first end of the three-inch piece 

 is square, and fits up closely to cleat 

 jB. If it is " out of square," let the 

 end project just beyond the edge of 

 the rule and cut off a narrow strip, 

 which squares the end, and makes 

 the piece right for cutting into 

 slides without loss of material. 

 Proceeding upon the same plan, I 

 make an arrangement for cutting 

 the three-inch strips. 



The diamond is undoubtedly the 

 best instrument for cutting glass, 

 but it is expensive, and requires 

 some skill to use it properly ; but I 

 have done nearly all of my work 

 with the cheap glass-cutters, which 

 are sold for twenty-five cents, and 

 with entire satisfaction ; indeed, I 

 think they make a smoother cut 

 than the diamond and consequently 

 require less grinding. If one of 

 these cutters is used simply for work 

 it will last a long time. 



Care should be taken to secure 

 thin, clear glass. Ordinary window- 

 glass is too thick, but in nearly 

 every place where glass i» sold there 

 may be found pieces excellent in 

 quality and sufficiently thin. The 

 thickness should not exceed -^ of 

 an inch. 



The slides being cut, the grind- 

 ing follows. This is done upon an 

 ordinary grindstone, and the car- 

 dinal principle of the process is to 

 grind with the stone turning from 

 the slides. As the ends of the slide 



are the most difficult, it is best to 

 begin with them. The corners of 

 the edge are first ground off by 

 holding the slide as at ^, in Fig. 15. 

 Both sides being treated in the same 

 way, the slide is held as at B, and 

 drawn the whole length of the end, 

 so the stone will not grind up into 

 the centre of the slide. The ends 

 being finished, the sides are treated 

 in the same way, the corners first, 

 and then the slide is held as at C, 

 drawing the length of the slide from 

 end to end. The slide is to be held 

 firmly, as close down to the stone 

 as possible, and the sides of the slide 

 parallel with those of the stone, 

 except when grinding off the 

 corners. The object in grinding off 

 the corners first is to prevent little 

 pieces from splitting off the sides 

 of the glass. The amount ground 

 off from the corners need be only a 

 very little, just enough to make a 

 straight line from end to end. A 

 little experience will soon teach how 

 much. The edge may be finished in 

 two ways, like 2> and ^ in Fig. 15, 

 the latter being my favorite method. 

 The ends of the slide being most 

 difficult to grind, a good deal of 

 time may be saved by grinding off 

 the sides of the three-inch strips 

 before cutting them into slides. 



When grinding, it is best, as soon 

 as a slide is finished, to drop it into 

 a dish of water, for if laid one upon 

 another, or upon any hard substance, 

 the slides are quite likely to get 

 scratched by the particles worn from 

 the stone. If the grinding has been 

 well done and the stone not too 

 coarse, the edges will present a very 

 neat appearance without additional 

 labor, but if their edges are polished 

 they will equal those of the dealers. 

 In glass-factories polishing is done 

 upon wooden wheels with the sur- 

 faces charged with emery, or some 

 other polishing substance. I have 

 succeeded very well by the follow- 



