250 T. Gaffeld on the action of Sunlight on Glass. 
record made at the end of each month, but a piece of glass 
taken in and laid aside at the same time to show the actual color 
unless exposure of y J 
shade of yellow or pink would ever be produced in any kind by 
sure to sunlight. 
other manufacturers to rae the defects cof their productions, 
f day. But my scruples have been all 
- (see Comptes Rendus, Jan. 14, 1867) the following statement: 
. r. . : & 53 t 
3 ee believe that there exists in commerce a single ee 
; & lo: 
action of the sun’s rays 
color of all or nearly all kinds of window glass. 
