The images I just found on-line to illustrate. I think they are from the various editions of von Scheel's "Mémoires d'artillerie …" and/or Gassendi's "Aide-Mémoire …."
Example : link
Example : link
The dimensions come from de Morla's "Tables …."
link
Here is a nice summary about the system of l'An XI, by Paul Dawson, in English :
link
I am sorry, I usually search for French info in French (my native language), and so often miss good info in English. Then I mangle that beautiful language with my posts. I really do apologize.
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"how was the "Horse Limber"?"
I really wasn't too sure about this model, as I tried to suggest. It is hard to really tell about a model from 1 photo in medium resolution. I was only about 85% sure that I was correctly guessing the manufacturer's intention for the other two models.
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"French horse artillery used 4lb pieces then 4lb and 6lb pieces"
And also 8-lbers.
And perhaps 12-lbers. The Russians tried heavy horse artillery in the Gatchina force in the late 1790's and started regular fielding of "battery horse artillery companies" with 12-lbers in late 1812/early 1813 for use with the better roads of western Europe.. I imagine the French also tried it at least once or twice.
I think all the French Guard artillery (including horse artillery?) went to Prussian (or Prussian-style) extra-heavy, long 6-inch howitzers ("à grand portée") for 1812 and later.
The last use of Gribeaval 4-pounders (outside of Iberia) was as regimental foot artillery for the Guard in Russia : 18 pieces, all lost.
Generalizations about artillery are OK, but I often find that they are not absolutes.