Not sure if this has been shown before...if so, my apologies...if not, it makes interesting reading
From the Oct. 1931 issue of "Popular Science".
http://blog.modernmechanix.com/2008...Qif=razor_blades_0.jpg&Qiv=thumbs&Qis=XL#qdig
From the Oct. 1931 issue of "Popular Science".
http://blog.modernmechanix.com/2008...Qif=razor_blades_0.jpg&Qiv=thumbs&Qis=XL#qdig