3 io 



WINDOWS AND SKYLIGHTS 



< J "x/+ Lagxrews 



ELEVATION 



SECTION 



PLAN 

 FIG. 154. DESIGN FOR WINDOW FRAME WITH COUNTERBALANCED SASH. 



Amount of Light Required. The amount of glazed surface re- 

 quired in mill buildings depends upon the use to which the building is 

 to be put, the material used in glazing, the location and angle of the 

 windows and skylights, and the clearness of the atmosphere. In glazing 

 windows for mills and factories in which the determination of color 

 is a necessary part of the work, care should be used to obtain a clear 

 white glass for the reason that the ordinary commercial glass breaks 

 up the light passing through it so that the determination of color is 

 difficult. 



