One or the major flaws of period recipes is the lack of a universal form of measurement. Phrases like 'take a goodly sum of XXX' or 'add to XXX enough of YYY' and even 'cook until done' are very common in historical recipe books. I think the cook dictating the recipes figured if you were making specialty dishes, you knew the basic methods of creating said dishes.

Try to reason out this one: 'Make a coffin and in it place XXX.' Bet you'd never guess it was a way to say make a pie shell and fill it with XXX. If you were lucky the recipe would differentiate between a sweet pie or a savory pie shell. (Substituting coffin for pie would certainly give the old children's rhyme "Sing a Song of Sixpence" a different sound - not to mention dismay many parents.)

Often a recipe would merely list the ingredients and simply say 'mix well and serve.' Take this example of a recipe for Parsley sauce:

"Take percely, and grynde hit wib vynegre
and a litel brede and salt,
and strayne it burgh a straynour,
and serue it forbe."

Translated this recipe states: Take parsley and grind it with vinegar and a little bread and salt and strain it through a strainer and serve it forth.

The parsley (which, though currently used as a garnish, is actually a tasty herb) gives the sauce the initial flavor as well as color. The vinegar adds some extra liquid, as well as tartness. These items are ground together with breadcrumbs, which act as a thickener and then pushed through a strainer or sieve. This prevents larger chunks to interrupt the sauce while allowing the thickness to remain. I personally like this sauce with poached fish.

Good luck in your pursuits and Bon Appetit!