I used Clive Thompson’s Weird Old Book Finder and searched on “shaving,” whereupon it delivered the above book from 1844.
I was particularly struck by this sentence in the preface:
To remove the beard pleasantly and expeditiously, (two very desirable things,) the razor requires to be held in a certain position, and moved in a certain direction, and if that is not attended to, the best razor that was ever made will not cut smoothly.
Even in 1844 the distinction between comfort (“pleasantly”) and efficiency (“expeditiously”) was noted, along with the understanding that both are important for a good shave.