I admit that I am slow to find which thread to put things into sometimes. I try to read before I ask questions, but I don't catch everything.
Ralf already found that I miss things in French, and that is my best non-English language - silly American!
Here is an 1851 internal letter.
I am hopeful that someone can simply tell me when this rate was active (from start date to end date). I assume it was the rate for every 4 adarmes, but please correct me if I am incorrect!