Ancient fonts were always large enough to allow for total immersion, and our present custom of baptism by affusion, or sprinkling, is only permitted, not enjoined by the rubric.
"Our Homeland Churches and How to Study Them"
Sidney Heath
There can be little doubt that affusion was practiced instead of immersion, at the discretion of the Priest, in ancient as well as in modern times.
"The American Church Dictionary and Cyclopedia"
William James Miller
And some of our friends have been pleas'd to think, that we have made no unusefull addition to this Experiment, by shewing a way, how in a moment our Liquor may be depriv'd of its Blewness, and restor'd to it again by the affusion of a very few drops of Liquors, which have neither of them any Colour at all of their own.
"Experiments and Considerations Touching Colours (1664)"
Robert Boyle