William Shakespeare (1849-1931)

All the exercises of the old masters were practiced on the vowel "ah," so typical of the open throat and freedom of the tongue. As these two masters did not refer at all to the note, we must conclude that they meant: when mastery over the breath and open throat during singing is attained, the note now unimpeded, looks after itself. 

This is the meaning of such expressions as "placing the voice," the voice "on the breath," or the "breath under the note," So the art of the singer, though a subtle one, is yet quite simple. He bring his notes one by one into the fold. Each sounds to its appropriate tone spaces automatically accompany it. 

Try the experiment of whispering the "Ah" softly for five seconds, then in the same breath increase the pressure for five seconds. Observe that on adding to the pressure, the breath is inclined to slip away. Practise the until you succeed in prolonging the "Ah" without losing command. 

Next prolong the "Ah" for ten seconds on the lowest sound of the talking voice, much lower than you usually sing. The cords are now brought nearer together; and being slightly tightened their edges offer some resistance to the breath pressure which sets them in vibration. The slackness of the cords, by allowing any uncontrolled breath to slip through, and the fact that while sounds such low notes we cannot hold the throat, makes the exercise valuable for strengthening the breath muscles and one which should be practiced often. 

The ancient Greeks accustomed their orators to recite the longest verses in one breath, on the lowest tones of the voice. They thus cultivated control over their respiration. Try this by counting up to forty on your lowest possible tones in one breath. It is a capital exercise.

—William Shakespeare, Plain Words on Singing, G. P. Putnam's Sons, 1924: 21-22

The use of "Ah" on the "lowest sound in the talking voice, much lower than you usually sing" is the very same teaching Herman Klein called "singing position," which appears in Hidden in Plain Sight: The Hermann Klein Phono-Vocal Method based upon the Famous School of Manuel García (VoiceTalkPublications 2013).

We can gather from this that Old School voice teachers were far from quixotic. Rather, their teachings were of the tried and true sort, having been gleaned from observing and following nature.