Cut throat razor, 1750-1850.

UNKNOWN - JUNE 24: Steel blade with ebony handle. The 'open' or 'cutthroat' razor, shaped with a long handle and iron blades, was first developed in Ancient Rome or Greece. It remained the only practical razor until the nineteenth century, when improvements in steel manufacture meant that blades were sharper, and could be resharpened. In 1900, most men went regularly to the barber or shaved periodically at home. Better off customers would have their own personal sets of razors, one for each day of the week. Advances in razor technology in the twentieth century, including the introduction of the electric razor, changed shaving habits. Today the majority of men shave daily in their homes, using a wide variety of equipment. (Photo by SSPL/Getty Images)