Literals

[Porges]

Babbage uses the term “litteral constant” (once!) in his Passages from the Life of a Philosopher; it appears that in his case he means an inline constant as opposed to one loaded from a constant storage card.

‘literal’ for a constant in old mathematics texts seems to mean the opposite of what it does in programming nowadays. For example, the ‘literal lunar theory’ used named variables (a, b, c, hence ‘literal’) instead of numeric constants… so Babbage's usage seems to be the opposite of what was standard, although it's hard to be sure as he doesn't explain the term.

[Porges]

See, e.g., Lunar Theory from the 1740s to the 1870s – A Sketch:

Because he substituted numerical values of the arbitrary constants from the start, his theory is called a numerical theory; it is to be contrasted with a literal theory in which the coefficients are expressed as algebraic functions of the arbitrary constants.