This chap belonged to the great army of unconscious exposers, and the "switch" was quite apparent to all save the most careless observers.
His apparatus consisted of a fancy rack on which three sharp razors were displayed, and a large bandanna handkerchief, in which there were several pockets of the size to hold a razor, the three dull razors being loaded in this.

After testing the edge of the sharp razors, he pretended to wipe them, one by one, with the handkerchief, and under cover of this he made the "switch" for the dull ones, which he proceeded to swallow in the orthodox fashion.

His work was crude, and the crowd was inclined to poke fun at him.
I have seen one of these performers on the street, in London, swallow a borrowed umbrella, after carefully wiping the ferrule, and then return it to its owner only slightly dampened from its unusual journey.

A borrowed watch was swallowed by the same performer, and while one end of the chain hung from the lips, the incredulous onlookers were invited to place their ears against his chest and listen to the ticking of the watch, which had passed as far into the aesophagus as the chain would allow.
The following anecdote from the Carlisle Journal, shows that playing with sword-swallowing is about as dangerous as playing with fire.
DISTRESSING OCCURRENCE On Monday evening last, a man named William Dempster, a juggler of inferior dexterity while exhibiting his tricks in a public house in Botchergate, kept by a person named Purdy, actually accomplished the sad reality of one of those feats, with the semblance only of which he intended to amuse his audience.

Having introduced into his throat a common table knife which he was intending to swallow, he accidentally slipped his hold, and the knife passed into his stomach.