28 THE POPULAR SCIENCE MONTHLY. 



Tht search for material ended, the work of construction may 

 begin. Two duplicate copies of the cartoon are first made. One 

 operation suffices to accomplish this. The cartoon is laid on a 

 large table, and beneath it are two sheets of similar paper and two 

 sheets of ordinary black transfer paper arranged alternately. By 

 passing a small revolving wheel over the outlines of the cartoon, 

 the tracings are quickly and accurately made. Each space is then 

 numbered correspondingly on both tracings, and one of them is 

 cut up to make patterns for the glass-cutter. An ingenious dis- 

 secting instrument is used for this purpose. It consists of a pair 

 of double-edged shears, which, in cutting, removes a strip of paper 

 just the width of the lead which will separate the fragments of 

 glass when they are finally bound together. In this way each 

 pattern is precisely the size required. When the glass is ready to 

 be put together in the window, there is very little coaxing to be 

 done to get it into place. 



The picture-window has now reached the most critical stage in 

 its development. The paper patterns are to find suitable counter- 

 parts in glass, and upon the nicety with which this substitution is 

 accomplished depends the effect of the entire work. Nothing is 

 left undone that will assist the glass-cutter in forming correct 

 color- judgments. Throughout the entire process, and here par- 

 ticularly, the work progresses under precisely those conditions 

 that are best calculated to make surprises and incongruities im- 

 possible when the whole shall be completed. A sheet of plain 

 glass, the size of the cartoon, is laid over the undissected tracing. 

 Outlines of the intended lead bands are then painted on the clear 

 glass in black lines of corresponding width. On the model thus 

 prepared the paper patterns are stuck by means of a little wax. 

 It is now ready to be taken to the figure-room, where it is placed 

 directly in front of a large window, and the slow work of substi- 

 tuting colored glass for paper begins. The position in which the 

 completed window is to be placed must constantly be borne in 

 mind, and the treatment adopted be made to conform to the re- 

 quirements of light and neighborhood. A window that will be 

 effective when seen against a clear northern sky will probably be 

 somewhat dull if turned to some other point of the compass and 

 seen against a dark background of brick walls and shadows, while 

 a window that would be a delight under these more somber con- 

 ditions would be insupportably glaring against the stronger light. 

 Consideration must also be paid to whether the window is to be 

 seen commonly at long or short range, and to the general color 

 tone of neighboring windows and walls. 



Piece by piece the paper patterns are removed, and the shaped 

 fragments of glass take their place. Each fragment is obtained 

 by repeated trials until just the right effect is secured. When the 



