330 



Popular Science Monthly 



Making the Scallops on 

 Plate Glass 



The Tool Grasps the Edge of the Glass 

 Plate and Bites It Off With a Tooth or Point 



WILLIAM SPANGLER, a resident 

 of Illinois, has invented an im- 

 proved glass-chipping tool which has for 

 its purpose the ornamentation of plate 

 glass by scalloping. The 

 ordinary glass-chipping tool 

 can be used on glass of one 

 thickness only, and when a 

 plate of another thickness is 

 to be chipped another tool 

 must be employed. The 

 tool grasps the edge of the 

 plate between a bearing 

 point and a bit and bites it 

 off with a tooth, or point, 

 provided for the purpose. 

 In order that the same tool 

 may operate successfully 

 with varying thicknesses of 

 glass it is necessary that the 

 space between the bearing 

 I)oint and tlie bit be adjust- 

 able in two directions — 

 transversely of the edge of 

 the glass and longitudinally 

 of the handle of the tool, so 

 that the bearing point shall 

 im])inge the glass at varying 

 <listaiices from the edge. 



The invention referred to 

 provides for tills double ad- 

 justment of the jaws. 



How Heat Is Measured 

 with the Eye 



NOW that man has succeeded in 

 obtaining artificial heats that al- 

 most rival the intensity of the sun, the 

 accomplishment has made the demand 

 upon him that, in harnessing this terrific 

 heat for industrial purposes, he shall 

 devise some means of measuring it. For 

 many years after electric heat was known 

 and used industrially the exact tempera- 

 tures which existed were only guessed at. 

 Recently, an instrument known as the 

 thermo-electric pyrometer has come into 

 use, but this ingenious type of thermom- 

 eter has the serious limitation that it 

 will melt when the temperature has 

 passed a certain point. The latest 

 development in heat-measuring devices 

 is an optical instrument, which, while it 

 is placed in operation many feet from the 

 heat source, will measure the tempera- 

 ture with a fine degree of accuracy. 



The "sight pyrometer," as it might be 

 called, really takes up the measurement 

 of temperatures where the ordinary 

 pyrometer leaves off. It can safely and 

 accurately measure heat at temperatures 

 as high as 7200 degrees Fahrenheit. The 



MLasurinu Htat-Trcating Temperatures With the 

 "Sight Pyrometer" Many Feet from the Heat Source 



