mdhsphotographs: City of Baltimore, Bureau of Research, ‘Ext.’ Polytechnic Institute. 200 East North Avenue, Baltimore, Maryland; June, 1931. Hughes Company. 8 x 10 inch negative. Baltimore City Life Museum Collection, Maryland Historical Society, MC6125 North Avenue series. … The white lines and disfiguration of this acetate negative is what is known as channeling.  [emphasis mine]

mdhsphotographs: City of Baltimore, Bureau of Research, ‘Ext.’ Polytechnic Institute. 200 East North Avenue, Baltimore, Maryland; June, 1931. Hughes Company. 8 x 10 inch negative. Baltimore City Life Museum Collection, Maryland Historical Society, MC6125 North Avenue series. … The white lines and disfiguration of this acetate negative is what is known as channeling[emphasis mine]