230 



A. DAIGGER & COMPANY, CHICAGO, U. S. A. 



371l(a) 



3711(a) PYROMETER TUBES OF ALUNDUM. These tubes are impervious to 

 gases under normal pressures through a wide range of temperatures. 

 They have a high deformation point which, in connection with their im- 

 perviousness and high thermal conductivity, are very valuable in pyro- 

 metric work. 



They will stand rapid changes of temperature, and are surprisingly long- 

 lived when treated in a manner similar to the porcelain tubes. 

 Tube iV inch bore, }& inch outside diameter. 



12 inches long, each $2.40 



18 inches long, each 3.60 



24 inches long, each 4.80 



30 inches long, each 6.00 



36 inches long, each 7.20 



PYROMETER TUBES, Porcelain, see No. 4095. 



QUARTZ GLASS APPARATUS TRANSPARENT 



:mi(b), etc. 



